- Full List of INPUT Keywords
- System variables
- Variables related to input files
- Plane wave related variables
- Numerical atomic orbitals related variables
- Electronic structure
- basis_type
- ks_solver
- nbands
- nspin
- smearing_method
- smearing_sigma
- smearing_sigma_temp
- mixing_type
- mixing_beta
- mixing_beta_mag
- mixing_ndim
- mixing_restart
- mixing_dmr
- mixing_gg0
- mixing_gg0_mag
- mixing_gg0_min
- mixing_angle
- mixing_tau
- mixing_dftu
- gamma_only
- printe
- scf_nmax
- scf_thr
- scf_thr_type
- chg_extrap
- lspinorb
- noncolin
- soc_lambda
- Electronic structure (SDFT)
- Geometry relaxation
- Variables related to output information
- out_mul
- out_freq_elec
- out_chg
- out_pot
- out_dm
- out_dm1
- out_wfc_pw
- out_wfc_r
- out_wfc_lcao
- out_dos
- out_band
- out_proj_band
- out_stru
- out_bandgap
- out_level
- out_alllog
- out_mat_hs
- out_mat_r
- out_mat_hs2
- out_mat_t
- out_mat_dh
- out_mat_xc
- out_app_flag
- out_ndigits
- out_interval
- out_element_info
- restart_save
- restart_load
- rpa
- nbands_istate
- bands_to_print
- Density of states
- NAOs
- DeePKS
- OFDFT: orbital free density functional theory
- Electric field and dipole correction
- Gate field (compensating charge)
- Exact Exchange
- exx_hybrid_alpha
- exx_hse_omega
- exx_separate_loop
- exx_hybrid_step
- exx_mixing_beta
- exx_lambda
- exx_pca_threshold
- exx_c_threshold
- exx_v_threshold
- exx_dm_threshold
- exx_c_grad_threshold
- exx_v_grad_threshold
- exx_schwarz_threshold
- exx_cauchy_threshold
- exx_cauchy_force_threshold
- exx_cauchy_stress_threshold
- exx_ccp_threshold
- exx_ccp_rmesh_times
- exx_distribute_type
- exx_opt_orb_lmax
- exx_opt_orb_ecut
- exx_opt_orb_tolerence
- exx_real_number
- rpa_ccp_rmesh_times
- Molecular dynamics
- md_type
- md_nstep
- md_dt
- md_thermostat
- md_tfirst, md_tlast
- md_restart
- md_restartfreq
- md_dumpfreq
- dump_force
- dump_vel
- dump_virial
- md_seed
- md_tfreq
- md_tchain
- md_pmode
- md_prec_level
- ref_cell_factor
- md_pcouple
- md_pfirst, md_plast
- md_pfreq
- md_pchain
- lj_rcut
- lj_epsilon
- lj_sigma
- pot_file
- msst_direction
- msst_vel
- msst_vis
- msst_tscale
- msst_qmass
- md_damp
- md_tolerance
- md_nraise
- cal_syns
- dmax
- DFT+U correction
- vdW correction
- Berry phase and wannier90 interface
- TDDFT: time dependent density functional theory
- td_edm
- td_print_eij
- td_propagator
- td_vext
- td_vext_dire
- td_stype
- td_ttype
- td_tstart
- td_tend
- td_lcut1
- td_lcut2
- td_gauss_freq
- td_gauss_phase
- td_gauss_sigma
- td_gauss_t0
- td_gauss_amp
- td_trape_freq
- td_trape_phase
- td_trape_t1
- td_trape_t2
- td_trape_t3
- td_trape_amp
- td_trigo_freq1
- td_trigo_freq2
- td_trigo_phase1
- td_trigo_phase2
- td_trigo_amp
- td_heavi_t0
- td_heavi_amp
- out_dipole
- out_efield
- ocp
- ocp_set
- Variables useful for debugging
- Electronic conductivities
- Implicit solvation model
- Quasiatomic Orbital (QO) analysis
These variables are used to control general system parameters.
- Type: String
- Description: In each run, ABACUS will generate a subdirectory in the working directory. This subdirectory contains all the information of the run. The subdirectory name has the format: OUT.suffix, where the
suffix
is the name you can pick up for your convenience. - Default: ABACUS
- Type: Integer
- Description: Number of different atom species in this calculation. If this value is not equal to the atom species in the STRU file, ABACUS will stop and quit. If not set or set to 0, ABACUS will automatically set it to the atom species in the STRU file.
- Default: 0
-
Type: String
-
Description: Specify the type of calculation.
- scf: do self-consistent electronic structure calculation
- relax: do structure relaxation calculation, one can use
relax_nmax
to decide how many ionic relaxations you want - cell-relax: do variable-cell relaxation calculation
- nscf: do the non self-consistent electronic structure calculations. For this option, you need a charge density file. For nscf calculations with planewave basis set, pw_diag_thr should be <= 1e-3
- get_pchg: For LCAO basis. Please see the explanation for variable
nbands_istate
andbands_to_print
- get_wf: Envelope function for LCAO basis. Please see the explanation for variable
nbands_istate
- md: molecular dynamics
- test_memory : checks memory required for the calculation. The number is not quite reliable, please use it with care
- test_neighbour : only performs neighbouring atom search, please specify a positive search_radius manually.
- gen_bessel : generates projectors (a series of Bessel functions) for DeePKS; see also keywords bessel_descriptor_lmax, bessel_descriptor_rcut and bessel_descriptor_tolerence. A file named
jle.orb
will be generated which contains the projectors. An example is provided in examples/H2O-deepks-pw - get_S : only works for multi-k calculation with LCAO basis. Generates and writes the overlap matrix to a file named
SR.csr
in the working directory. The format of the file will be the same as that generated by out_mat_hs2
-
Default: scf
- Type: String
- Description: choose the energy solver.
- ksdft: Kohn-Sham density functional theory
- ofdft: orbital-free density functional theory
- sdft: stochastic density functional theory
- tddft: real-time time-dependent density functional theory (TDDFT)
- lj: Leonard Jones potential
- dp: DeeP potential, see details in md.md
- Default: ksdft
- Type: Integer
- Description: takes value 1, 0 or -1.
- -1: No symmetry will be considered. It is recommended to set -1 for non-colinear + soc calculations, where time reversal symmetry is broken sometimes.
- 0: Only time reversal symmetry would be considered in symmetry operations, which implied k point and -k point would be treated as a single k point with twice the weight.
- 1: Symmetry analysis will be performed to determine the type of Bravais lattice and associated symmetry operations. (point groups, space groups, primitive cells, and irreducible k-points)
- Default:
- 0:
- if calculation==md/nscf/get_pchg/get_wf/get_S or gamma_only==True;
- If (dft_fuctional==hse/hf/pbe0/scan0/opt_orb or rpa==True). Currently symmetry==1 is not supported in EXX (exact exchange) calculation.
- 1: else
- 0:
- Type: Real
- Description: The accuracy for symmetry judgment. Usually the default value is good enough, but if the lattice parameters or atom positions in STRU file is not accurate enough, this value should be enlarged.
Note: if calculation==cell_relax, this value can be dynamically changed corresponding to the variation of accuracy of the lattice parameters and atom positions during the relaxation. The new value will be printed in
OUT.${suffix}/running_cell-relax.log
in that case. - Default: 1.0e-6
- Unit: Bohr
- Type: Boolean
- Availability: symmetry==1
- Description: Control how to deal with error in symmetry analysis due to inaccurate lattice parameters or atom positions in STRU file, especially useful when calculation==cell-relax
- False: quit with an error message
- True: automatically set symmetry to 0 and continue running without symmetry analysis
- Default: True
- Type: Integer
- Description: divide all processors into kpar groups, and k points will be distributed among each group. The value taken should be less than or equal to the number of k points as well as the number of MPI processes.
- Default: 1
- Type: Integer
- Description: divide all processors into bndpar groups, and bands (only stochastic orbitals now) will be distributed among each group. It should be larger than 0.
- Default: 1
-
Type: String
-
Description: Specifies the type of Bravias lattice. When set to
none
, the three lattice vectors are supplied explicitly in STRU file. When set to a certain Bravais lattice type, there is no need to provide lattice vector, but a few lattice parameters might be required. For more information regarding this parameter, consult the page on STRU file.Available options are (correspondence with ibrav in QE(Quantum Espresso) is given in parenthesis):
- none: free structure
- sc: simple cubic (1)
- fcc: face-centered cubic (2)
- bcc: body-centered cubic (3)
- hexagonal: hexagonal (4)
- trigonal: trigonal (5)
- st: simple tetragonal (6)
- bct: body-centered tetragonal (7)
- so: orthorhombic (8)
- baco: base-centered orthorhombic (9)
- fco: face-centered orthorhombic (10)
- bco: body-centered orthorhombic (11)
- sm: simple monoclinic (12)
- bacm: base-centered monoclinic (13)
- triclinic: triclinic (14)
-
Default: none
-
Type: Integer
-
Description: enable the experimental feature psi_initializer, to support use numerical atomic orbitals initialize wavefunction (
basis_type pw
case).NOTE: this feature is not well-implemented for
nspin 4
case (closed presently), and cannot use withcalculation nscf
/esolver_type sdft
cases. Available options are:- 0: disable psi_initializer
- 1: enable psi_initializer
-
Default: 0
-
Type: String
-
Description: Only useful for plane wave basis only now. It is the name of the starting wave functions. In the future. we should also make this variable available for localized orbitals set.
Available options are:
- atomic: from atomic pseudo wave functions. If they are not enough, other wave functions are initialized with random numbers.
- atomic+random: add small random numbers on atomic pseudo-wavefunctions
- file: from binary files
WAVEFUNC*.dat
, which are output by setting out_wfc_pw to2
. - random: random numbers
with
psi_initializer 1
, two more options are supported:- nao: from numerical atomic orbitals. If they are not enough, other wave functions are initialized with random numbers.
- nao+random: add small random numbers on numerical atomic orbitals
-
Default: atomic
-
Type: String
-
Description: This variable is used for both plane wave set and localized orbitals set. It indicates the type of starting density.
- atomic: the density is starting from the summation of the atomic density of single atoms.
- file: the density will be read in from a binary file
charge-density.dat
first. If it does not exist, the charge density will be read in from cube files. Besides, when you donspin=1
calculation, you only need the density file SPIN1_CHG.cube. However, if you donspin=2
calculation, you also need the density file SPIN2_CHG.cube. The density file should be output with these names if you set out_chg = 1 in INPUT file.
-
Default: atomic
-
Type: Boolean
-
Description:
- True: read the atom velocity (atomic unit : 1 a.u. = 21.877 Angstrom/fs) from the atom file (
STRU
) and determine the initial temperature md_tfirst. If md_tfirst is unset or less than zero,init_vel
is autoset to betrue
. - False: assign value to atom velocity using Gaussian distributed random numbers.
- True: read the atom velocity (atomic unit : 1 a.u. = 21.877 Angstrom/fs) from the atom file (
-
Default: False
-
Type: Real
-
Description:
- 0.0: the total number of electrons will be calculated by the sum of valence electrons (i.e. assuming neutral system).
>0.0
: this denotes the total number of electrons in the system. Must be less than 2*nbands.
-
Default: 0.0
- Type: Real
- Description:
the total number of electrons will be calculated by
nelec
+nelec_delta
. - Default: 0.0
- Type: Real
- Description:
- 0.0: no constrain apply to system.
>0.0
: this denotes the difference number of electrons between spin-up and spin-down in the system. The range of value must in [-nelec ~ nelec]. It is one method of constraint DFT, the fermi energy level will separate to E_Fermi_up and E_Fermi_down.
- Default: 0.0
-
Type: String
-
Description: In our package, the XC functional can either be set explicitly using the
dft_functional
keyword inINPUT
file. Ifdft_functional
is not specified, ABACUS will use the xc functional indicated in the pseudopotential file. On the other hand, if dft_functional is specified, it will overwrite the functional from pseudopotentials and performs calculation with whichever functional the user prefers. We further offer two ways of supplying exchange-correlation functional. The first is using 'short-hand' names such as 'LDA', 'PBE', 'SCAN'. A complete list of 'short-hand' expressions can be found in the source code. The other way is only available when compiling with LIBXC, and it allows for supplying exchange-correlation functionals as combinations of LIBXC keywords for functional components, joined by a plus sign, for example, 'dft_functional='LDA_X_1D_EXPONENTIAL+LDA_C_1D_CSC'. The list of LIBXC keywords can be found on its website. In this way, we support all the LDA,GGA and mGGA functionals provided by LIBXC.Furthermore, the old INPUT parameter exx_hybrid_type for hybrid functionals has been absorbed into dft_functional. Options are
hf
(pure Hartree-Fock),pbe0
(PBE0),hse
(Note: in order to use HSE functional, LIBXC is required). Note also that HSE has been tested while PBE0 has NOT been fully tested yet, and the maximum CPU cores for running exx in parallel is$N(N+1)/2$ , with N being the number of atoms. And forces for hybrid functionals are not supported yet.If set to
opt_orb
, the program will not perform hybrid functional calculation. Instead, it is going to generate opt-ABFs as discussed in this article. -
Default: same as UPF file.
- Type: Real
- Description: specifies temperature when using temperature-dependent XC functionals (KSDT and so on).
- Default : 0.0
- Unit: Ry
- Type: Real
- Description: Cut-off of radial integration for pseudopotentials
- Default: 15
- Unit: Bohr
- Type: Integer
- Description:
- 0: use our own mesh for radial integration of pseudopotentials
- 1: use the mesh that is consistent with quantum espresso
- Default: 0
-
Type: Boolean
-
Description: Used only for nscf calculations.
- 0: no memory saving techniques are used.
- 1: a memory saving technique will be used for many k point calculations.
-
Default: 0
- Type: Integer
- Availability: pw base
- Description:
- 0: it will be set to the number of MPI processes. Normally, it is fine just leave it to the default value.
>0
: it specifies the number of processes used for carrying out diagonalization. Must be less than or equal to total number of MPI processes. Also, when cg diagonalization is used, diago_proc must be the same as the total number of MPI processes.
- Default: 0
- Type: Integer
- Description: If set to a natural number, a Cardinal B-spline interpolation will be used to calculate Structure Factor.
nbspline
represents the order of B-spline basis and a larger one can get more accurate results but cost more. It is turned off by default. - Default: -1
-
Type: Real
-
Description: Set the smallest allowed spacing between k points, unit in 1/bohr. It should be larger than 0.0, and suggest smaller than 0.25. When you have set this value > 0.0, then the KPT file is unnecessary, and the number of K points nk_i = max(1, int(|b_i|/KSPACING_i)+1), where b_i is the reciprocal lattice vector. The default value 0.0 means that ABACUS will read the applied KPT file. If only one value is set (such as
kspacing 0.5
), then kspacing values of a/b/c direction are all set to it; and one can also set 3 values to set the kspacing value for a/b/c direction separately (such as:kspacing 0.5 0.6 0.7
).Note: if gamma_only is set to be true, kspacing is invalid.
-
Default: 0.0
- Type: Real
- Description: a factor related to the allowed minimum distance between two atoms. At the beginning, ABACUS will check the structure, and if the distance of two atoms is shorter than min_dist_coef*(standard covalent bond length), we think this structure is unreasonable. If you want to calculate some structures in extreme conditions like high pressure, you should set this parameter as a smaller value or even 0.
- Default: 0.2
-
Type: String
-
Description: Specifies the computing device for ABACUS.
Available options are:
- cpu: for CPUs via Intel, AMD, or Other supported CPU devices
- gpu: for GPUs via CUDA or ROCm.
Known limitations:
- pw basis: required by the
gpu
acceleration options - cg/bpcg/dav ks_solver: required by the
gpu
acceleration options
-
Default: cpu
-
Type: String
-
Description: Specifies the precision of the PW_SCF calculation.
Available options are:
- single: single precision
- double: double precision
Known limitations:
- pw basis: required by the
single
precision options - cg/bpcg/dav ks_solver: required by the
single
precision options
-
Default: double
These variables are used to control parameters related to input files.
- Type: String
- Description: the name of the structure file
- Containing various information about atom species, including pseudopotential files, local orbitals files, cell information, atom positions, and whether atoms should be allowed to move.
- Refer to Doc
- Default: STRU
- Type: String
- Description: the name of the k-points file
- In atomic orbitals basis with
gamma_only
set to true, theKPT
file is unnecessary, because aKPT
file will be generated automatically. - When more than one k-points are required, an explicit
KPT
file is mandatory. - Refer to Doc
- In atomic orbitals basis with
- Default: KPT
- Type: String
- Description: the pseudopotential file directory
- This parameter is combined with the pseudopotential filenames in the STRU file to form the complete pseudopotential file paths.
- Example: set pseudo_dir to "../" with "Si.upf" which specified under "ATOMIC_SPECIES" in STRU file, ABACUS will open the pseudopotential file in path "../Si.upf".
- Default: ""
- Type: String
- Description: the orbital file directory
- This parameter is combined with orbital filenames in the STRU file to form the complete orbital file paths.
- Example: set orbital_dir to "../" with "Si.orb" which specified under "NUMERICAL_ORBITAL" in STRU file, ABACUS will open the orbital file in path "../Si.orb".
- Default: ""
- Type: String
- Description: Indicates the location of files, such as electron density (
SPIN1_CHG.cube
), required as a starting point.- Example: './' implies the files to be read are located in the working directory.
- Default: OUT.$suffix
- Type: String
- Availability: Using ABACUS with Wannier90.
- Description: The name of the input file related to Wannier90.
- Default: "none"
These variables are used to control the plane wave related parameters.
- Type: Real
- Description: Energy cutoff for plane wave functions, the unit is Rydberg. Note that even for localized orbitals basis, you still need to setup an energy cutoff for this system. Because our local pseudopotential parts and the related force are calculated from plane wave basis set, etc. Also, because our orbitals are generated by matching localized orbitals to a chosen set of wave functions from a certain energy cutoff, this set of localize orbitals is most accurate under this same plane wave energy cutoff.
- Default: 50
- Type: Real
- Description: Energy cutoff for charge density and potential, the unit is Rydberg. For norm-conserving pseudopotential you should stick to the default value, you can reduce it by a little but it will introduce noise especially on forces and stress. For ultrasoft pseudopotential a larger value than the default is often desirable (
ecutrho
= 8 to 12 timesecutwfc
, typically). The use of gradient-corrected functional, especially in cells with vacuum, or for pseudopotential without non-linear core correction, usually requires an higher values ofecutrho
to be accurately converged. - Default: 4*ecutwfc
-
Type: Integer
-
Description: If set to a positive number, then the three variables specify the numbers of FFT grid points in x, y, z directions, respectively. If set to 0, the number will be calculated from ecutrho.
Note: You must specify all three dimensions for this setting to be used.
-
Default: 0
-
Type: Integer
-
Description: If set to a positive number, then the three variables specify the numbers of FFT grid (for the dense part of charge density in ultrasoft pseudopotential) points in x, y, z directions, respectively. If set to 0, the number will be calculated from ecutwfc.
Note: You must specify all three dimensions for this setting to be used.
Note: These parameters must be used combined with nx,ny,nz. If nx,ny,nz are unset, ndx,ndy,ndz are used as nx,ny,nz.
-
Default: 0
- Type: Integer
- Description: Only useful for plane wave basis only now. It is the random seed to initialize wave functions. Only positive integers are available.
- Default:0
- Type: Real
- Description: Only used when you use
ks_solver = cg/dav/dav_subspace/bpcg
. It indicates the threshold for the first electronic iteration, from the second iteration the pw_diag_thr will be updated automatically. For nscf calculations with planewave basis set, pw_diag_thr should be <= 1e-3. - Default: 0.01
- Type: Integer
- Description: Only useful when you use
ks_solver = cg/dav/dav_subspace/bpcg
. It indicates the maximal iteration number for cg/david/dav_subspace/bpcg method. - Default: 40
- Type: Integer
- Description: Only useful when you use
ks_solver = dav
orks_solver = dav_subspace
. It indicates dimension of workspace(number of wavefunction packets, at least 2 needed) for the Davidson method. A larger value may yield a smaller number of iterations in the algorithm but uses more memory and more CPU time in subspace diagonalization. - Default: 4
- Type: bool
- Description: Only useful when you use
ks_solver = dav_subspace
. IfTRUE
, all the empty states are diagonalized at the same level of accuracy of the occupied ones. Otherwise the empty states are diagonalized using a larger threshold (10-5) (this should not affect total energy, forces, and other ground-state properties). - Default: false
- Type: Real
- Description: Used in variable-cell molecular dynamics (or in stress calculation). See erf_sigma in detail.
- Default: 0.0
- Unit: Ry
- Type: Integer
- Description: Set the mode of FFTW.
- 0: FFTW_ESTIMATE
- 1: FFTW_MEASURE
- 2: FFTW_PATIENT
- 3: FFTW_EXHAUSTIVE
- Default: 0
- Type: Real
- Description: Used in variable-cell molecular dynamics (or in stress calculation). See erf_sigma in detail.
- Default: 0.0
- Unit: Ry
-
Type: Real
-
Description: In order to recover the accuracy of a constant energy cutoff calculation, the kinetic functional is modified, which is used in variable-cell molecular dynamics (or in stress calculation).
erf_ecut is the value of the constant energy cutoff; erf_height and erf_sigma are the height and the width of the energy step for reciprocal vectors whose square modulus is greater than erf_ecut. In the kinetic energy, G^2 is replaced by G^2 + erf_height * (1 + erf ( (G^2 - erf_ecut)/erf_sigma) )
See: M. Bernasconi et al., J. Phys. Chem. Solids 56, 501 (1995), doi:10.1016/0022-3697(94)00228-2
-
Default: 0.1
-
Unit: Ry
These variables are used to control the numerical atomic orbitals related parameters.
- Type: Integer
- Description: In LCAO calculations, we arrange the total number of processors in an 2D array, so that we can partition the wavefunction matrix (number of bands*total size of atomic orbital basis) and distribute them in this 2D array. When the system is large, we group processors into sizes of nb2d, so that multiple processors take care of one row block (a group of atomic orbitals) in the wavefunction matrix. If set to 0, nb2d will be automatically set in the program according to the size of atomic orbital basis:
- if size <= 500 : nb2d = 1
- if 500 < size <= 1000 : nb2d = 32
- if size > 1000 : nb2d = 64;
- Default: 0
- Type: Integer
- Description: If not equals to 2, then the maximum l channels on LCAO is set to lmaxmax. If 2, then the number of l channels will be read from the LCAO data sets. Normally no input should be supplied for this variable so that it is kept as its default.
- Default: 2.
- Type: Real
- Description: Energy cutoff (in Ry) for two-center integrals in LCAO. The two-center integration table are obtained via a k space integral whose upper limit is about sqrt(
lcao_ecut
). - Default:
ecutwfc
- Type: Real
-
Description: k spacing (in Bohr${}^{-1}$) for two-center integrals. The two-center integration table are obtained via a k space integral on a uniform grid with spacing
lcao_dk
. - Default: 0.01
- Type: Real
- Description: r spacing (in Bohr) of the integration table of two-center integrals.
- Default: 0.01
- Type: Real
- Description: Maximum distance (in Bohr) for the two-center integration table.
- Default: 30
- Type: Real
- Description: Searching radius in finding the neighbouring atoms. By default the radius will be automatically determined by the cutoffs of orbitals and nonlocal beta projectors.
- Default: -1
- Unit: Bohr
- Type: Boolean
- Description: If True, periodic images will be included in searching for the neighbouring atoms. If False, periodic images will be ignored.
- Default: True
- Type: Integer
- Description: In the matrix operation of grid integral, bx/by/bz grids (in x, y, z directions) are treated as a whole as a matrix element. A different value will affect the calculation speed. The default is 0, which means abacus will automatically calculate these values.
- Default: 0
These variables are used to control the electronic structure and geometry relaxation calculations.
- Type: String
- Description: Choose the basis set.
- pw: Using plane-wave basis set only.
- lcao: Using localized atomic orbital sets.
- lcao_in_pw: Expand the localized atomic set in plane-wave basis, non-self-consistent field calculation not tested.
- Default: pw
-
Type: String
-
Description: Choose the diagonalization methods for the Hamiltonian matrix expanded in a certain basis set.
For plane-wave basis,
- cg: cg method.
- bpcg: bpcg method, which is a block-parallel Conjugate Gradient (CG) method, typically exhibits higher acceleration in a GPU environment.
- dav: the Davidson algorithm.
For atomic orbitals basis,
- genelpa: This method should be used if you choose localized orbitals.
- scalapack_gvx: Scalapack can also be used for localized orbitals.
- cusolver: (Unavailable currently, it will be fixed in future versions) This method needs building with the cusolver component for lcao and at least one gpu is available.
If you set ks_solver=
genelpa
for basis_type=pw
, the program will be stopped with an error message:genelpa can not be used with plane wave basis.
Then the user has to correct the input file and restart the calculation.
-
Default: cg (plane-wave basis), or genelpa (localized atomic orbital basis, if compiling option
USE_ELPA
has been set), scalapack_gvx, (localized atomic orbital basis, if compiling optionUSE_ELPA
has not been set)
- Type: Integer
- Description: The number of Kohn-Sham orbitals to calculate. It is recommended to setup this value, especially when smearing techniques are utilized, more bands should be included.
- Default:
- nspin=1: max(1.2*occupied_bands, occupied_bands + 10)
- nspin=2: max(1.2*nelec_spin, nelec_spin + 10), in which nelec_spin = max(nelec_spin_up, nelec_spin_down)
- nspin=4: max(1.2*nelec, nelec + 20)
- Type: Integer
- Description: The number of spin components of wave functions.
- 1: Spin degeneracy
- 2: Collinear spin polarized.
- 4: For the case of noncollinear polarized, nspin will be automatically set to 4 without being specified by the user.
- Default: 1
- Type: String
-
Description: It indicates which occupation and smearing method is used in the calculation.
- fixed: fixed occupations (available for non-coductors only)
- gauss or gaussian: Gaussian smearing method.
- mp: methfessel-paxton smearing method; recommended for metals.
- mp2: 2-nd methfessel-paxton smearing method; recommended for metals.
- mv or cold: marzari-vanderbilt smearing method.
-
fd: Fermi-Dirac smearing method:
$f=1/{1+\exp[(E-\mu)/kT]}$ and smearing_sigma below is the temperature$T$ (in Ry).
- Default: gauss
- Type: Real
- Description: Energy range for smearing.
- Default: 0.015
- Unit: Ry
- Type: Real
- Description: Energy range for smearing,
smearing_sigma
= 1/2 kBsmearing_sigma_temp
. - Default: 2 *
smearing_sigma
/ kB. - Unit: K
-
Type: String
-
Description: Charge mixing methods.
- plain: Just simple mixing.
- pulay: Standard Pulay method. P. Pulay Chemical Physics Letters, (1980)
- broyden: Simplified modified Broyden method. D.D. Johnson Physical Review B (1988)
In general, the convergence of the Broyden method is slightly faster than that of the Pulay method.
-
Default: broyden
-
Type: Real
-
Description: In general, the formula of charge mixing can be written as
$\rho_{new} = \rho_{old} + \beta * \rho_{update}$ , where$\rho_{new}$ represents the new charge density after charge mixing,$\rho_{old}$ represents the charge density in previous step,$\rho_{update}$ is obtained through various mixing methods, and$\beta$ is set by the parametermixing_beta
. A lower value of 'mixing_beta' results in less influence of$\rho_{update}$ on$\rho_{new}$ , making the self-consistent field (SCF) calculation more stable. However, it may require more steps to achieve convergence. We recommend the following options:-
0.8:
nspin=1
-
0.4:
nspin=2
andnspin=4
-
0: keep charge density unchanged, usually used for restarting with
init_chg=file
or testing. -
0.1 or less: if convergence of SCF calculation is difficult to reach, please try
0 < mixing_beta < 0.1
.
Note: For low-dimensional large systems, the setup of
mixing_beta=0.1
,mixing_ndim=20
, andmixing_gg0=1.0
usually works well. -
0.8:
-
Default: 0.8 for
nspin=1
, 0.4 fornspin=2
andnspin=4
.
- Type: Real
- Description: Mixing parameter of magnetic density.
- Default:
4*mixing_beta
, but the maximum value is 1.6.
Note that mixing_beta_mag
is not euqal to mixing_beta
means that mixing_beta_mag
and mixing_gg0_mag
exactly euqal to mixing_beta
and mixing_gg0
if you calculate an atomic system.
-
Type: Integer
-
Description: It indicates the mixing dimensions in Pulay or Broyden. Pulay and Broyden method use the density from previous mixing_ndim steps and do a charge mixing based on this density.
For systems that are difficult to converge, one could try increasing the value of 'mixing_ndim' to enhance the stability of the self-consistent field (SCF) calculation.
-
Default: 8
-
Type: double
-
Description: If the density difference between input and output
drho
is smaller thanmixing_restart
, SCF will restart at next step which means SCF will restart by using output charge density from perivos iteration as input charge density directly, and start a new mixing. Notice thatmixing_restart
will only take effect once in one SCF. -
Default: 0
-
Type: bool
-
Availability: Only for
mixing_restart>=0.0
-
Description: At n-th iteration which is calculated by
drho<mixing_restart
, SCF will start a mixing for real-space density matrix by using the same coefficiences as the mixing of charge density. -
Default: false
-
Type: Real
-
Description: Whether to perfom Kerker scaling for charge density.
-
>0: The high frequency wave vectors will be suppressed by multiplying a scaling factor
$\frac{k^2}{k^2+gg0^2}$ . Settingmixing_gg0 = 1.0
is normally a good starting point. Kerker preconditioner will be automatically turned off ifmixing_beta <= 0.1
. - 0: No Kerker scaling is performed.
For systems that are difficult to converge, particularly metallic systems, enabling Kerker scaling may aid in achieving convergence.
-
>0: The high frequency wave vectors will be suppressed by multiplying a scaling factor
-
Default: 1.0
- Type: Real
- Description: Whether to perfom Kerker preconditioner of magnetic density. Note: we do not recommand to open Kerker preconditioner of magnetic density unless the system is too hard to converge.
- Default: 0.0
- Type: Real
- Description: the minimum kerker coefficient
- Default: 0.1
- Type: Real
-
Availability: Only relevant for non-colinear calculations
nspin=4
. -
Description: Normal broyden mixing can give the converged result for a given magnetic configuration. If one is not interested in the energies of a given magnetic configuration but wants to determine the ground state by relaxing the magnetic moments’ directions, one cannot rely on the standard Broyden mixing algorithm. To enhance the ability to find correct magnetic configuration for non-colinear calculations, ABACUS implements a promising mixing method proposed by J. Phys. Soc. Jpn. 82 (2013) 114706. Here,
mixing_angle
is the angle mixing parameter. In fact, onlymixing_angle=1.0
is implemented currently.-
<=0: Normal broyden mixing for
$m_{x}, m_{y}, m_{z}$ -
>0: Angle mixing for the modulus
$|m|$ withmixing_angle=1.0
-
<=0: Normal broyden mixing for
- Default: -10.0
Note: In new angle mixing, you should set mixing_beta_mag >> mixing_beta
. The setup of mixing_beta=0.2
, mixing_beta_mag=1.0
usually works well.
- Type: Boolean
- Availability: Only relevant for meta-GGA calculations.
- Description: Whether to mix the kinetic energy density.
- True: The kinetic energy density will also be mixed. It seems for general cases, SCF converges fine even without this mixing. However, if there is difficulty in converging SCF for meta-GGA, it might be helpful to turn this on.
- False: The kinetic energy density will not be mixed.
- Default: False
- Type: Boolean
- Availability: Only relevant for DFT+U calculations.
- Description: Whether to mix the occupation matrices.
- True: The occupation matrices will also be mixed by plain mixing. From experience this is not very helpful if the +U calculation does not converge.
- False: The occupation matrices will not be mixed.
- Default: False
-
Type: Integer
-
Availability: Only used in localized orbitals set
-
Description: Whether to use gamma_only algorithm.
- 0: more than one k-point is used and the ABACUS is slower compared to the gamma only algorithm.
- 1: ABACUS uses gamma only, the algorithm is faster and you don't need to specify the k-points file.
Note: If gamma_only is set to 1, the KPT file will be overwritten. So make sure to turn off gamma_only for multi-k calculations.
-
Default: 0
- Type: Integer
- Description: Print out energy for each band for every printe step
- Default: 100
- Type: Integer
- Description: This variable indicates the maximal iteration number for electronic iterations.
- Default: 100
- Type: Real
- Description: It's the threshold for electronic iteration. It represents the charge density error between two sequential densities from electronic iterations. Usually for local orbitals, usually 1e-6 may be accurate enough.
- Default: 1.0e-9 (plane-wave basis), or 1.0e-7 (localized atomic orbital basis).
-
Type: Integer
-
Description: Choose the calculation method of convergence criterion.
-
1: the criterion is defined as
$\Delta\rho_G = \frac{1}{2}\iint{\frac{\Delta\rho(r)\Delta\rho(r')}{|r-r'|}d^3r d^3r'}$ . -
2: the criterion is defined as
$\Delta\rho_R = \int{|\Delta\rho(r)|d^3r}$ .
Note: This parameter is still under testing and the default setting is usually sufficient.
-
1: the criterion is defined as
-
Default: 1 (plane-wave basis), or 2 (localized atomic orbital basis).
- Type: String
- Description: Methods to do extrapolation of density when ABACUS is doing geometry relaxations or molecular dynamics.
- atomic: atomic extrapolation.
- first-order: first-order extrapolation.
- second-order: second-order extrapolation.
- Default: first-order (geometry relaxations), second-order (molecular dynamics), else atomic
- Type: Boolean
- Description: Whether to consider spin-orbital coupling effect in the calculation.
- True: Consider spin-orbital coupling effect, and
nspin
is also automatically set to 4. - False: Do not consider spin-orbital coupling effect.
- True: Consider spin-orbital coupling effect, and
- Default: False
- Type: Boolean
- Description: Whether to allow non-collinear polarization, in which case the coupling between spin up and spin down will be taken into account.
- True: Allow non-collinear polarization, and
nspin
is also automatically set to 4. - False: Do not allow non-collinear polarization.
- True: Allow non-collinear polarization, and
- Default: False
-
Type: Real
-
Availability: Relevant for soc calculations.
-
Description: Sometimes, for some real materials, both scalar-relativistic and full-relativistic can not describe the exact spin-orbit coupling. Artificial modulation may help in such cases.
soc_lambda
, which has value range [0.0, 1.0] , is used for modulate SOC effect.In particular,
soc_lambda 0.0
refers to scalar-relativistic case andsoc_lambda 1.0
refers to full-relativistic case. -
Default: 1.0
These variables are used to control the parameters of stochastic DFT (SDFT), mix stochastic-deterministic DFT (MDFT), or complete-basis Chebyshev method (CT). In the following text, stochastic DFT is used to refer to these three methods. We suggest using SDFT to calculate high-temperature systems and we only support smearing_method "fd". Both "scf" and "nscf" calculation are supported.
- Type: Integer
-
Availability: esolver_type =
sdft
-
Description: Different methods to do stochastic DFT
- 1: Calculate
$T_n(\hat{h})\ket{\chi}$ twice, where$T_n(x)$ is the n-th order Chebyshev polynomial and$\hat{h}=\frac{\hat{H}-\bar{E}}{\Delta E}$ owning eigenvalues$\in(-1,1)$ . This method cost less memory but is slower. - 2: Calculate
$T_n(\hat{h})\ket{\chi}$ once but needs much more memory. This method is much faster. Besides, it calculates$N_e$ with$\bra{\chi}\sqrt{\hat f}\sqrt{\hat f}\ket{\chi}$ , which needs a smaller nche_sto. However, when the memory is not enough, only method 1 can be used. - other: use 2
- 1: Calculate
- Default: 2
- Type: Integer or string
-
Availability: esolver_type =
sdft
-
Description: The number of stochastic orbitals
- > 0: Perform stochastic DFT.
Increasing the number of bands improves accuracy and reduces stochastic errors, which scale as
$1/\sqrt{N_{\chi}}$ ; To perform mixed stochastic-deterministic DFT, you should set nbands, which represents the number of KS orbitals. - 0: Perform Kohn-Sham DFT.
- all: All complete basis sets are used to replace stochastic orbitals with the Chebyshev method (CT), resulting in the same results as KSDFT without stochastic errors.
- > 0: Perform stochastic DFT.
Increasing the number of bands improves accuracy and reduces stochastic errors, which scale as
- Default: 256
- Type: Integer
- Availability: esolver_type =
sdft
- Description: Chebyshev expansion orders for stochastic DFT.
- Default: 100
- Type: Real
-
Availability: esolver_type =
sdft
-
Description: Trial energy to guess the lower bound of eigen energies of the Hamiltonian Operator
$\hat{H}$ . - Default: 0.0
- Unit: Ry
- Type: Real
-
Availability: esolver_type =
sdft
-
Description: Trial energy to guess the upper bound of eigen energies of the Hamiltonian Operator
$\hat{H}$ . - Default: 0.0
- Unit: Ry
- Type: Integer
-
Availability: esolver_type =
sdft
-
Description: The random seed to generate stochastic orbitals.
- >= 0: Stochastic orbitals have the form of
$\exp(i2\pi\theta(G))$ , where$\theta$ is a uniform distribution in$(0,1)$ . - 0: the seed is decided by time(NULL).
- <= -1: Stochastic orbitals have the form of
$\pm1$ with equal probability. - -1: the seed is decided by time(NULL).
- >= 0: Stochastic orbitals have the form of
- Default: 0
- Type: Real
- Availability: esolver_type =
sdft
- Description: Stochastic wave functions are initialized in a large box generated by "4*
initsto_ecut
".initsto_ecut
should be larger than ecutwfc. In this method, SDFT results are the same when using different cores. Besides, coefficients of the same G are the same when ecutwfc is rising to initsto_ecut. If it is smaller than ecutwfc, it will be turned off. - Default: 0.0
- Unit: Ry
- Type: Integer
- Availability: esolver_type =
sdft
- Description: Frequency (once each initsto_freq steps) to generate new stochastic orbitals when running md.
- positive integer: Update stochastic orbitals
- 0: Never change stochastic orbitals.
- Default: 0
- Type: Integer
- Availability: method_sto =
2
and out_dos =True
or cal_cond =True
- Description: Make memory cost to 1/npart_sto times of the previous one when running the post process of SDFT like DOS or conductivities.
- Default: 1
These variables are used to control the geometry relaxation.
- Type: String
- Description: The methods to do geometry optimization.
- cg: using the conjugate gradient (CG) algorithm. Note that there are two implementations of the conjugate gradient (CG) method, see relax_new.
- bfgs: using the Broyden–Fletcher–Goldfarb–Shanno (BFGS) algorithm.
- cg_bfgs: using the CG method for the initial steps, and switching to BFGS method when the force convergence is smaller than relax_cg_thr.
- sd: using the steepest descent (SD) algorithm.
- fire: the Fast Inertial Relaxation Engine method (FIRE), a kind of molecular-dynamics-based relaxation algorithm, is implemented in the molecular dynamics (MD) module. The algorithm can be used by setting calculation to
md
and md_type tofire
. Also ionic velocities should be set in this case. See fire for more details.
- Default: cg
- Type: Boolean
- Description: At around the end of 2022 we made a new implementation of the Conjugate Gradient (CG) method for
relax
andcell-relax
calculations. But the old implementation was also kept.- True: use the new implementation of CG method for
relax
andcell-relax
calculations. - False: use the old implementation of CG method for
relax
andcell-relax
calculations.
- True: use the new implementation of CG method for
- Default: True
- Type: Real
- Availability: only used when
relax_new
set toTrue
- Description: The paramether controls the size of the first conjugate gradient step. A smaller value means the first step along a new CG direction is smaller. This might be helpful for large systems, where it is safer to take a smaller initial step to prevent the collapse of the whole configuration.
- Default: 0.5
- Type: Integer
- Description: The maximal number of ionic iteration steps, the minimum value is 1.
- Default: 1
- Type: Real
- Description: When move-method is set to
cg_bfgs
, a mixed algorithm of conjugate gradient (CG) method and Broyden–Fletcher–Goldfarb–Shanno (BFGS) method is used. The ions first move according to CG method, then switched to BFGS method when the maximum of force on atoms is reduced below the CG force threshold, which is set by this parameter. - Default: 0.5
- Unit: eV/Angstrom
- Type: Boolean
- Description:
- True calculate the force at the end of the electronic iteration
- False no force calculation at the end of the electronic iteration
- Default: False if
calculation
is set toscf
, True ifcalculation
is set tocell-relax
,relax
, ormd
.
- Type: Real
- Description: Threshold of the force convergence in Ry/Bohr. The threshold is compared with the largest force among all of the atoms. The recommended value for using atomic orbitals is 0.04 eV/Angstrom (0.0016 Ry/Bohr). The parameter is equivalent to force_thr_ev except for the unit. You may choose either you like.
- Default: 0.001
- Unit: Ry/Bohr (25.7112 eV/Angstrom)
- Type: Real
- Description: Threshold of the force convergence in eV/Angstrom. The threshold is compared with the largest force among all of the atoms. The recommended value for using atomic orbitals is 0.04 eV/Angstrom (0.0016 Ry/Bohr). The parameter is equivalent to force_thr except for the unit. You may choose either you like.
- Default: 0.0257112
- Unit: eV/Angstrom (0.03889 Ry/Bohr)
- Type: Real
- Description: The calculated force will be set to 0 when it is smaller than the parameter
force_thr_ev2
. - Default: 0.0
- Unit: eV/Angstrom
- Type: Real
- Description: This variable controls the Wolfe condition for Broyden–Fletcher–Goldfarb–Shanno (BFGS) algorithm used in geometry relaxation. You can look into the paper Phys.Chem.Chem.Phys.,2000,2,2177 for more information.
- Default: 0.01
- Type: Real
- Description: This variable controls the Wolfe condition for Broyden–Fletcher–Goldfarb–Shanno (BFGS) algorithm used in geometry relaxation. You can look into the paper Phys.Chem.Chem.Phys.,2000,2,2177 for more information.
- Default: 0.5
- Type: Real
- Description: This variable is for geometry optimization. It stands for the maximal movement of all the atoms. The sum of the movements from all atoms can be increased during the optimization steps. However, it can not be larger than
relax_bfgs_rmax
- Unit: Bohr
- Default: 0.8
- Type: Real
- Description: This variable is for geometry optimization. It indicates the minimal movement of all the atoms. When the movement of all the atoms is smaller than relax_bfgs_rmin Bohr, and the force convergence is still not achieved, the calculation will break down.
- Default: 1e-5
- Unit: Bohr
- Type: Real
- Description: This variable is for geometry optimization. It stands for the sum of initial movements of all of the atoms.
- Default: 0.5
- Unit: Bohr
- Type: Boolean
- Description:
- True: calculate the stress at the end of the electronic iteration
- False: no calculation of the stress at the end of the electronic iteration
- Default: True if
calculation
iscell-relax
, False otherwise.
- Type: Real
- Description: The threshold of the stress convergence. The threshold is compared with the largest component of the stress tensor.
- Default: 0.5
- Unit: kbar
- Type: Real
- Description: The external pressures along three axes. Positive input value is taken as compressive stress.
- Default: 0
- Unit: kbar
- Type: String
- Availability: only used when
calculation
set tocell-relax
- Description: Axes that are fixed during cell relaxation. Possible choices are:
- None: default; all of the axes can relax
- volume: relaxation with fixed volume
- shape: fix shape but change volume (i.e. only lattice constant changes)
- a: fix a axis during relaxation
- b: fix b axis during relaxation
- c: fix c axis during relaxation
- ab: fix both a and b axes during relaxation
- ac: fix both a and c axes during relaxation
- bc: fix both b and c axes during relaxation
Note : fixed_axes = "shape" and "volume" are only available for relax_new = True
- Default: None
- Type: Boolean
- Availability: Must be used along with relax_new set to True, and a specific latname must be provided
- Description:
- True: the lattice type will be preserved during relaxation
- False: No restrictions are exerted during relaxation in terms of lattice type
Note: it is possible to use
fixed_ibrav
withfixed_axes
, but please make sure you know what you are doing. For example, if we are doing relaxation of a simple cubic lattice (latname
= "sc"), and we usefixed_ibrav
along withfixed_axes
= "volume", then the cell is never allowed to move and as a result, the relaxation never converges.
- Default: False
- Type: Boolean
- Description:
- True: The direct coordinates of atoms will be preserved during variable-cell relaxation.
- False: No restrictions are exerted on positions of all atoms. However, users can still fix certain components of certain atoms by using the
m
keyword inSTRU
file. For the latter option, check the end of this instruction.
- Default: False
- Type: Real
- Description: Used in the construction of the pseudopotential tables. It should exceed the maximum linear contraction of the cell during a simulation.
- Default: 1.2
These variables are used to control the output of properties.
- Type: Boolean
- Availability: Numerical atomic orbital basis
- Description: Whether to print the Mulliken population analysis result into
OUT.${suffix}/mulliken.txt
. In molecular dynamics calculations, the output frequency is controlled by out_interval. - Default: False
- Type: Integer
- Description: The output frequency of the charge density (controlled by out_chg), wavefunction (controlled by out_wfc_pw or out_wfc_r), and density matrix of localized orbitals (controlled by out_dm).
- >0: Output them every
out_freq_elec
iteration numbers in electronic iterations. - 0: Output them when the electronic iteration is converged or reaches the maximal iteration number.
- >0: Output them every
- Default: 0
-
Type: Boolean
-
Description: Whether to output the charge density (in Bohr^-3) on real space grids into the density files in the folder
OUT.${suffix}
. The files are named as:- npsin = 1: SPIN1_CHG.cube;
- npsin = 2: SPIN1_CHG.cube, and SPIN2_CHG.cube;
- npsin = 4: SPIN1_CHG.cube, SPIN2_CHG.cube, SPIN3_CHG.cube, and SPIN4_CHG.cube.
The circle order of the charge density on real space grids is: x is the outer loop, then y and finally z (z is moving fastest).
If EXX(exact exchange) is calculated, (i.e. dft_fuctional==hse/hf/pbe0/scan0/opt_orb or rpa==True), the Hexx(R) files will be output in the folder
OUT.${suffix}
too, which can be read in NSCF calculation. -
Default: False
- Type: Integer
-
Description:
-
1: Output the total local potential (i.e., local pseudopotential + Hartree potential + XC potential + external electric field (if exists) + dipole correction potential (if exists) + ...) on real space grids (in Ry) into files in the folder
OUT.${suffix}
. The files are named as:- npsin = 1: SPIN1_POT.cube;
- npsin = 2: SPIN1_POT.cube, and SPIN2_POT.cube;
- npsin = 4: SPIN1_POT.cube, SPIN2_POT.cube, SPIN3_POT.cube, and SPIN4_POT.cube.
-
2: Output the electrostatic potential on real space grids into
OUT.${suffix}/ElecStaticPot.cube
. The Python script namedtools/average_pot/aveElecStatPot.py
can be used to calculate the average electrostatic potential along the z-axis and outputs it into ElecStaticPot_AVE.Please note that the total local potential refers to the local component of the self-consistent potential, excluding the non-local pseudopotential. The distinction between the local potential and the electrostatic potential is as follows: local potential = electrostatic potential + XC potential.
-
- Default: 0
- Type: Boolean
- Availability: Numerical atomic orbital basis (gamma-only algorithm)
- Description: Whether to output the density matrix of localized orbitals into files in the folder
OUT.${suffix}
. The files are named as:- npsin = 1: SPIN1_DM;
- npsin = 2: SPIN1_DM, and SPIN2_DM.
- Default: False
- Type: Boolean
- Availability: Numerical atomic orbital basis (multi-k points)
- Description: Whether to output the density matrix of localized orbitals into files in the folder
OUT.${suffix}
. The density matrices are written in the format of sparse matrices, as mentioned in out_mat_hs2. The files are named as:- npsin = 1: data-DMR-sparse_SPIN0.csr;
- npsin = 2: data-DMR-sparse_SPIN0.csr, and data-DMR-sparse_SPIN1.csr.
- Default: False
- Type: Integer
- Availability: Plane wave basis or get_wf calculation in numerical atomic orbital basis
-
Description:
- 1: Output the coefficients of wave functions into text files named
OUT.${suffix}/WAVEFUNC${K}.txt
, where ${K} is the index of k points. - 2: results are stored in binary files named
OUT.${suffix}/WAVEFUNC${K}.dat
.
- 1: Output the coefficients of wave functions into text files named
- Default: 0
- Type: Boolean
- Availability: Plane wave basis or get_wf calculation in numerical atomic orbital basis
-
Description: Whether to output real-space wave functions into
OUT.suffix/wfc_realspace/wfc_realspace_${K}_${B}
, where${K}
is the index of k points,${B}
is the index of bands. - Default: False
-
Type: Integer
-
Availability: Numerical atomic orbital basis
-
Description: Whether to output the wavefunction coefficients into files in the folder
OUT.${suffix}
. The files are named as:- 0: no output
- 1: (txt format)
- gamma-only:
LOWF_GAMMA_S1.txt
; - non-gamma-only:
LOWF_K_${k}.txt
, where${k}
is the index of k points.
- gamma-only:
- 2: (binary format)
- gamma-only:
LOWF_GAMMA_S1.dat
; - non-gamma-only:
LOWF_K_${k}.dat
, where${k}
is the index of k points.
- gamma-only:
The corresponding sequence of the orbitals can be seen in Basis Set.
Also controled by out_interval and out_app_flag.
-
Default: Flase
- Type: Boolean
- Description: Whether to output the density of states (DOS). For more information, refer to the dos.md.
- Default: False
- Type: Boolean Integer(optional)
- Description: Whether to output the band structure (in eV), optionally output precision can be set by a second parameter, default is 8. For more information, refer to the band.md
- Default: False
- Type: Boolean
- Description: Whether to output the projected band structure. For more information, refer to the band.md
- Default: False
- Type: Boolean
-
Description: Whether to output structure files per ionic step in geometry relaxation calculations into
OUT.${suffix}/STRU_ION${istep}_D
, where${istep}
is the ionic step. - Default: False
- Type: Boolean
-
Description: Whether to print the bandgap per electronic iteration into
OUT.${suffix}/running_${calculation}.log
. The value of bandgaps can be obtained by searching for the keyword: - Default: False
-
Type: String
-
Description: Control the output level of information in
OUT.${suffix}/running_${calculation}.log
.- ie: electronic iteration level, which prints useful information for electronic iterations;
- i: geometry relaxation level, which prints some information for geometry relaxations additionally;
- m: molecular dynamics level, which does not print some information for simplicity.
-
Default: ie
- Type: Boolean
-
Description: Whether to print information into individual logs from all ranks in an MPI run.
- True: Information from each rank will be written into individual files named
OUT.${suffix}/running_${calculation}_${rank+1}.log
. - False: Information will only be written from rank 0 into a file named
OUT.${suffix}/running_${calculation}.log
.
- True: Information from each rank will be written into individual files named
- Default: False
- Type: Boolean Integer(optional)
- Availability: Numerical atomic orbital basis
- Description: Whether to print the upper triangular part of the Hamiltonian matrices (in Ry) and overlap matrices for each k point into files in the directory
OUT.${suffix}
. The second number controls precision. For more information, please refer to hs_matrix.md. Also controled by out_interval and out_app_flag. - Default: False 8
- Type: Boolean
- Availability: Numerical atomic orbital basis (not gamma-only algorithm)
- Description: Whether to print the matrix representation of the position matrix (in Bohr) into a file named
data-rR-tr
in the directoryOUT.${suffix}
. For more information, please refer to position_matrix.md. - Default: False
- Type: Boolean
- Availability: Numerical atomic orbital basis (not gamma-only algorithm)
-
Description: Whether to print files containing the Hamiltonian matrix
$H(R)$ (in Ry) and overlap matrix$S(R)$ into files in the directoryOUT.${suffix}
. For more information, please refer to hs_matrix.md. - Default: False
- Type: Boolean
- Availability: Numerical atomic orbital basis (not gamma-only algorithm)
-
Description: For LCAO calculations, if out_mat_t is set to 1, ABACUS will generate files containing the kinetic energy matrix
$T(R)$ (in Ry). The format will be the same as the Hamiltonian matrix$H(R)$ and overlap matrix$S(R)$ as mentioned in out_mat_hs2. The name of the files will bedata-TR-sparse_SPIN0.csr
and so on. Also controled by out_interval and out_app_flag. - Default: False
- Type: Boolean
- Availability: Numerical atomic orbital basis (not gamma-only algorithm)
-
Description: Whether to print files containing the derivatives of the Hamiltonian matrix (in Ry/Bohr). The format will be the same as the Hamiltonian matrix
$H(R)$ and overlap matrix$S(R)$ as mentioned in out_mat_hs2. The name of the files will bedata-dHRx-sparse_SPIN0.csr
and so on. Also controled by out_interval and out_app_flag. - Default: False
- Type: Boolean
- Availability: Numerical atomic orbital basis
-
Description: Whether to print the upper triangular part of the exchange-correlation matrices in Kohn-Sham orbital representation (unit: Ry):
$\braket{\psi_i|V_\text{xc}^\text{(semi-)local}+V_\text{exx}+V_\text{DFTU}|\psi_j}$ for each k point into files in the directoryOUT.${suffix}
, which is useful for the subsequent GW calculation. (Note that currently DeePKS term is not included. ) The files are namedk-$k-Vxc
, the meaning of$k
corresponding to k point and spin is same as hs_matrix.md. The band (KS orbital) energy for each (k-point, spin, band) will be printed in the fileOUT.${suffix}/vxc_out
. If EXX is calculated, the local and EXX part of band energy will also be printed inOUT.${suffix}/vxc_local_out
andOUT.${suffix}/vxc_exx_out
, respectively. All thevxc*_out
files contains 3 integers (nk, nspin, nband) followed by nk*nspin*nband lines of energy Hartree and eV. - Default: False
- Type: Boolean
- Availability: Numerical atomic orbital basis
- Description: Whether to print Hamiltonian matrices H(R)/density matrics DM(R) in npz format. This feature does not work for gamma-only calculations. Currently only intended for internal usage.
- Default: False
- Type: Boolean
- Availability: Numerical atomic orbital basis
- Description: Reads density matrix DM(R) in npz format and creates electron density on grids. This feature does not work for gamma-only calculations. Only supports serial calculations. Currently only intended for internal usage.
- Default: False
- Type: Boolean
- Availability: Numerical atomic orbital basis (not gamma-only algorithm)
-
Description: Whether to output
$r(R)$ ,$H(R)$ ,$S(R)$ ,$T(R)$ ,$dH(R)$ ,$H(k)$ ,$S(k)$ and$wfc(k)$ matrices in an append manner during molecular dynamics calculations. Check input parameters out_mat_r, out_mat_hs2, out_mat_t, out_mat_dh, out_mat_hs and out_wfc_lcao for more information. - Default: true
- Type: Integar
- Availability:
out_mat_hs 1
case presently. - Description: Controls the length of decimal part of output data, such as charge density, Hamiltonian matrix, Overlap matrix and so on.
- Default: 8
- Type: Integer
- Availability: Numerical atomic orbital basis
-
Description: Control the interval for printing Mulliken population analysis,
$r(R)$ ,$H(R)$ ,$S(R)$ ,$T(R)$ ,$dH(R)$ ,$H(k)$ ,$S(k)$ and$wfc(k)$ matrices during molecular dynamics calculations. Check input parameters out_mul, out_mat_r, out_mat_hs2, out_mat_t, out_mat_dh, out_mat_hs and out_wfc_lcao for more information, respectively. - Default: 1
- Type: Boolean
-
Description: Whether to print element information into files in the directory
OUT.${suffix}/${element_label}
, including pseudopotential and orbital information of the element (in atomic Ryberg units). - Default: False
-
Type: Boolean
-
Availability: Numerical atomic orbital basis
-
Description: Whether to save charge density files per ionic step, which are used to restart calculations. According to the value of read_file_dir:
- auto: These files are saved in folder
OUT.${suffix}/restart/
; - other: These files are saved in folder
${read_file_dir}/restart/
.
If EXX(exact exchange) is calculated (i.e. dft_fuctional==hse/hf/pbe0/scan0/opt_orb or rpa==True), the Hexx(k) files for each k-point will also be saved in the above folder, which can be read in EXX calculation with restart_load==True.
- auto: These files are saved in folder
-
Default: False
-
Type: Boolean
-
Availability: Numerical atomic orbital basis
-
Description: If restart_save is set to true and an electronic iteration is finished, calculations can be restarted from the charge density file, which are saved in the former calculation. Please ensure read_file_dir is correct, and the charge density file exist.
If EXX(exact exchange) is calculated (i.e. dft_fuctional==hse/hf/pbe0/scan0/opt_orb or rpa==True), the Hexx(k) files in the same folder for each k-point will also be read.
-
Default: False
- Type: Boolean
- Description: Generate output files used in rpa calculations.
- Default: False
- Type: Integer
-
Availability: Only for LCAO, used when
calculation = get_wf
orcalculation = get_pchg
. -
Description: The number of bands around the Fermi level you would like to calculate.
get_wf
means to calculate the envelope functions of wave functions$\Psi_{i}=\Sigma_{\mu}C_{i\mu}\Phi_{\mu}$ , where$\Psi_{i}$ is the ith wave function with the band index$i$ and$\Phi_{\mu}$ is the localized atomic orbital set.get_pchg
means to calculate the density of each wave function$|\Psi_{i}|^{2}$ . Specifically, suppose we have highest occupied bands at 100th wave functions. And if you set this variable to 5, it will print five wave functions from 96th to 105th. But before all this can be carried out, the wave functions coefficients should be first calculated and written into a file by setting the flagout_wfc_lcao = 1
. - Default: 5
- Type: String
- Availability: For both PW and LCAO. When
basis_type = lcao
, only used whencalculation = get_pchg
. - Description: Specifies the bands to calculate the charge density for, using a space-separated string of 0s and 1s, providing a more flexible selection compared to
nbands_istate
. Each digit in the string corresponds to a band, starting from the first band. A1
indicates that the charge density should be calculated for that band, while a0
means the band will be ignored. The parameter allows a compact and flexible notation (similar toocp_set
), for example the syntax1 4*0 5*1 0
is used to denote the selection of bands:1
means calculate for the first band,4*0
skips the next four bands,5*1
means calculate for the following five bands, and the final0
skips the next band. It's essential that the total count of bands does not exceed the total number of bands (nbands
); otherwise, it results in an error, and the process exits. The input string must contain only numbers and the asterisk (*
) for repetition, ensuring correct format and intention of band selection. - Default: none
These variables are used to control the calculation of DOS. Detailed introduction
- Type: Real
- Description: the step size in writing Density of States (DOS)
- Default: 0.01
- Unit: eV
- Type: Real
- Description: the width of the Gaussian factor when obtaining smeared Density of States (DOS)
- Default: 0.07
- Unit: eV
- Type: Real
- Description: Defines the energy range of DOS output as (emax-emin)*(1+dos_scale), centered at (emax+emin)/2. This parameter will be used when dos_emin and dos_emax are not set.
- Default: 0.01
- Unit: eV
- Type: Real
-
Description: the minimal range for Density of States (DOS)
- If set, "dos_scale" will be ignored.
-
Default: Minimal eigenenergy of
$\hat{H}$ - Unit: eV
- Type: Real
-
Description: the maximal range for Density of States (DOS)
- If set, "dos_scale" will be ignored.
-
Default: Maximal eigenenergy of
$\hat{H}$ - Unit: eV
- Type: Integer The order of Chebyshev expansions when using Stochastic Density Functional Theory (SDFT) to calculate DOS.
- Default: 100
These variables are used to control the generation of numerical atomic orbitals (NAOs), whose radial parts are linear combinations of spherical Bessel functions with a node (i.e., evaluate to zero) at the cutoff radius.
In plane-wave-based calculations, necessary information will be printed into OUT.${suffix}/orb_matrix.${i}.dat
, which serves as an input file for the generation of NAOs. Please check SIAB package for more information.
- Type: Real
-
Description: "Energy cutoff" (in Ry) of spherical Bessel functions. The number of spherical Bessel functions that constitute the radial parts of NAOs is determined by sqrt(
bessel_nao_ecut
)$\times$bessel_nao_rcut
/$\pi$. -
Default:
ecutwfc
- Type: Real
- Description: tolerance when searching for the zeros of spherical Bessel functions.
- Default: 1.0e-12
- Type: Real
- Description: Cutoff radius (in Bohr) and the common node of spherical Bessel functions used to construct the NAOs.
- Default: 6.0
- Type: Boolean
-
Description: if True, NAOs will be smoothed near the cutoff radius by
$1-\exp\left(-\frac{(r-r_{cut})^2}{2\sigma^2}\right)$ . Seebessel_nao_rcut
for$r_{cut}$ andbessel_nao_sigma
for$\sigma$ . - Default: True
- Type: Real
- Description: Smoothing range (in Bohr). See also
bessel_nao_smooth
. - Default: 0.1
These variables are used to control the usage of DeePKS method (a comprehensive data-driven approach to improve the accuracy of DFT). Warning: this function is not robust enough for the current version. Please try the following variables at your own risk:
-
Type: Boolean
-
Availability: numerical atomic orbital basis
-
Description: print energy and force labels and descriptors for DeePKS training
-
Note: In
LCAO
calculation, the path of a numerical descriptor (anorb
file) is needed to be specified under theNUMERICAL_DESCRIPTOR
tag in theSTRU
file. For example:NUMERICAL_ORBITAL H_gga_8au_60Ry_2s1p.orb O_gga_7au_60Ry_2s2p1d.orb NUMERICAL_DESCRIPTOR jle.orb
-
Default: False
- Type: Boolean
- Availability: numerical atomic orbital basis
- Description: perform self-consistent field iteration in DeePKS method
- Note: A trained, traced model file is needed.
- Default: False
- Type: String
- Availability: numerical atomic orbital basis and
deepks_scf
is true - Description: the path of the trained, traced neural network model file generated by deepks-kit
- Default: None
- Type: Integer
- Availability:
gen_bessel
calculation - Description: the maximum angular momentum of the Bessel functions generated as the projectors in DeePKS
- NOte: To generate such projectors, set calculation type to
gen_bessel
in ABACUS. See also calculation. - Default: 2
- Type: Real
- Availability:
gen_bessel
calculation - Description: energy cutoff of Bessel functions
- Default: same as ecutwfc
- Unit: Ry
- Type: Real
- Availability:
gen_bessel
calculation - Description: tolerance for searching the zeros of Bessel functions
- Default: 1.0e-12
- Type: Real
- Availability:
gen_bessel
calculation - Description: cutoff radius of Bessel functions
- Default: 6.0
- Unit: Bohr
- Type: Boolean
- Availability:
gen_bessel
calculation - Description: smooth the Bessel functions at radius cutoff
- Default: False
- Type: Real
- Availability:
gen_bessel
calculation - Description: smooth parameter at the cutoff radius of projectors
- Default: 0.1
- Unit: Bohr
- Type: Boolean
- Availability: numerical atomic orbital basis and
deepks_scf
is true - Description: include bandgap label for DeePKS training
- Default: False
- Type: Boolean
- Description: generate files for constructing DeePKS unit test
- Note: Not relevant when running actual calculations. When set to 1, ABACUS needs to be run with only 1 process.
- Default: False
- Type: String
- Availability: OFDFT
-
Description: The type of KEDF (kinetic energy density functional).
- wt: Wang-Teter.
- tf: Thomas-Fermi.
- vw: von Weizsäcker.
-
tf+: TF$\rm{\lambda}$vW, the parameter
$\rm{\lambda}$ can be set byof_vw_weight
. - lkt: Luo-Karasiev-Trickey.
- Default: wt
- Type: String
- Availability: OFDFT
- Description: The optimization method used in OFDFT.
- cg1: Polak-Ribiere. Standard CG algorithm.
- cg2: Hager-Zhang (generally faster than cg1).
- tn: Truncated Newton algorithm.
- Default:tn
- Type: String
- Availability: OFDFT
- Description: Criterion used to check the convergence of OFDFT.
- energy: Ttotal energy changes less than
of_tole
. - potential: The norm of potential is less than
of_tolp
. - both: Both energy and potential must satisfy the convergence criterion.
- energy: Ttotal energy changes less than
- Default: energy
- Type: Real
- Availability: OFDFT
- Description: Tolerance of the energy change for determining the convergence.
- Default: 2e-6
- Unit: Ry
- Type: Real
- Availability: OFDFT
- Description: Tolerance of potential for determining the convergence.
- Default: 1e-5
- Unit: Ry
- Type: Real
- Availability: OFDFT with
of_kinetic=tf, tf+, wt
- Description: Weight of TF KEDF (kinetic energy density functional).
- Default: 1.0
- Type: Real
- Availability: OFDFT with
of_kinetic=vw, tf+, wt, lkt
- Description: Weight of vW KEDF (kinetic energy density functional).
- Default: 1.0
- Type: Real
-
Availability: OFDFT with
of_kinetic=wt
- Description: Parameter alpha of WT KEDF (kinetic energy density functional).
-
Default:
$5/6$
- Type: Real
-
Availability: OFDFT with
of_kinetic=wt
- Description: Parameter beta of WT KEDF (kinetic energy density functional).
-
Default:
$5/6$
- Type: Real
- Availability: OFDFT with
of_kinetic=wt
- Description: The average density of system.
- Default: 0.0
- Unit: Bohr^-3
- Type: Boolean
- Availability: OFDFT with
of_kinetic=wt
- Description: Whether to fix the average density rho0.
- True: rho0 will be fixed even if the volume of system has changed, it will be set to True automatically if
of_wt_rho0
is not zero. - False: rho0 will change if volume of system has changed.
- True: rho0 will be fixed even if the volume of system has changed, it will be set to True automatically if
- Default: False
- Type: Real
- Availability: OFDFT with
of_kinetic=lkt
- Description: Parameter a of LKT KEDF (kinetic energy density functional).
- Default: 1.3
- Type: Boolean
- Availability: OFDFT with
of_kinetic=wt
- Description: Whether to read in the kernel file.
- True: The kernel of WT KEDF (kinetic energy density functional) will be filled from the file specified by
of_kernel_file
. - False: The kernel of WT KEDF (kinetic energy density functional) will be filled from formula.
- True: The kernel of WT KEDF (kinetic energy density functional) will be filled from the file specified by
- Default: False
- Type: String
- Availability: OFDFT with
of_read_kernel=True
- Description: The name of WT kernel file.
- Default: WTkernel.txt
- Type: Boolean
- Availability: OFDFT
- Description: Whether to use full planewaves.
- True: Ecut will be ignored while collecting planewaves, so that all planewaves will be used in FFT.
- False: Only use the planewaves inside ecut, the same as KSDFT.
- Default: True
-
Type: Integer
-
Availability: OFDFT with
of_full_pw = True
-
Description: Specify the parity of FFT dimensions.
- 0: either odd or even.
- 1: odd only.
- 2: even only.
Note: Even dimensions may cause slight errors in FFT. It should be ignorable in ofdft calculation, but it may make Cardinal B-spline interpolation unstable, so please set
of_full_pw_dim = 1
ifnbspline != -1
. -
Default: 0
These variables are relevant to electric field and dipole correction
- Type: Boolean
- Description: added the electric field.
- True: A saw-like potential simulating an electric field is added to the bare ionic potential.
- False: Not added the electric field.
- Default: False
- Type: Boolean
- Availability: with dip_cor_flag = True and efield_flag = True.
- Description: Added a dipole correction to the bare ionic potential.
- True:A dipole correction is also added to the bare ionic potential.
- False: A dipole correction is not added to the bare ionic potential.
Note: If you want no electric field, parameter efield_amp should be zero. Must be used ONLY in a slab geometry for surface alculations, with the discontinuity FALLING IN THE EMPTY SPACE.
- Default: False
- Type: Integer
- Availability: with efield_flag = True.
-
Description: The direction of the electric field or dipole correction is parallel to the reciprocal lattice vector, so the potential is constant in planes defined by FFT grid points, efield_dir can set to 0, 1 or 2.
- 0: parallel to
$b_1=\frac{2\pi(a_2\times a_3)}{a_1\cdot(a_2\times a_3)}$ - 1: parallel to
$b_2=\frac{2\pi(a_3\times a_1)}{a_1\cdot(a_2\times a_3)}$ - 2: parallel to
$b_3=\frac{2\pi(a_1\times a_2)}{a_1\cdot(a_2\times a_3)}$
- 0: parallel to
- Default: 2
- Type: Real
- Availability: with efield_flag = True.
- Description: Position of the maximum of the saw-like potential along crystal axis efield_dir, within the unit cell, 0 <= efield_pos_max < 1.
- Default: Autoset to
center of vacuum - width of vacuum / 20
- Type: Real
- Availability: with efield_flag = True.
- Description: Zone in the unit cell where the saw-like potential decreases, 0 < efield_pos_dec < 1.
- Default: Autoset to
width of vacuum / 10
- Type: Real
- Availability: with efield_flag = True.
- Description: Amplitude of the electric field. The saw-like potential increases with slope efield_amp in the region from efield_pos_max+efield_pos_dec-1) to (efield_pos_max), then decreases until (efield_pos_max+efield_pos_dec), in units of the crystal vector efield_dir.
Note: The change of slope of this potential must be located in the empty region, or else unphysical forces will result.
- Default: 0.0
- Unit: a.u., 1 a.u. = 51.4220632*10^10 V/m.
These variables are relevant to gate field (compensating charge) Detailed introduction
- Type: Boolean
- Description: Controls the addition of compensating charge by a charged plate for charged cells.
- true: A charged plate is placed at the zgate position to add compensating charge. The direction is determined by efield_dir.
- false: No compensating charge is added.
- Default: false
- Type: Real
- Description: position of the charged plate in the unit cell
- Unit: Unit cell size
- Default: 0.5
- Constraints: 0 <= zgate < 1
- Type: Boolean
- Description: Controls the addition of a potential barrier to prevent electron spillover.
- true: A potential barrier is added from block_down to block_up with a height of block_height. If dip_cor_flag is set to true, efield_pos_dec is used to smoothly increase and decrease the potential barrier.
- false: No potential barrier is added.
- Default: false
- Type: Real
- Description: lower beginning of the potential barrier
- Unit: Unit cell size
- Default: 0.45
- Constraints: 0 <= block_down < block_up < 1
- Type: Real
- Description: upper beginning of the potential barrier
- Unit: Unit cell size
- Default: 0.55
- Constraints: 0 <= block_down < block_up < 1
- Type: Real
- Description: height of the potential barrier
- Unit: Rydberg
- Default: 0.1
These variables are relevant when using hybrid functionals.
Availablity: dft_functional==hse/hf/pbe0/scan0/opt_orb or rpa==True, and basis_type==lcao/lcao_in_pw
- Type: Real
-
Description: fraction of Fock exchange in hybrid functionals, so that
$E_{X}=\alpha E_{X}+(1-\alpha)E_{X,\text{LDA/GGA}}$ -
Default:
- 1: if dft_functional==hf
- 0.25: else
- Type: Real
-
Description: range-separation parameter in HSE functional, such that
$1/r=\text{erfc}(\omega r)/r+\text{erf}(\omega r)/r$ - Default: 0.11
- Type: Boolean
-
Description: There are two types of iterative approaches provided by ABACUS to evaluate Fock exchange.
- False: Start with a GGA-Loop, and then Hybrid-Loop, in which EXX Hamiltonian
$H_{exx}$ is updated with electronic iterations. - True: A two-step method is employed, i.e. in the inner iterations, density matrix is updated, while in the outer iterations,
$H_{exx}$ is calculated based on density matrix that converges in the inner iteration.
- False: Start with a GGA-Loop, and then Hybrid-Loop, in which EXX Hamiltonian
- Default: True
- Type: Integer
- Availability: exx_separate_loop==1
- Description: the maximal iteration number of the outer-loop, where the Fock exchange is calculated
- Default: 100
- Type: Real
- Availability: exx_separate_loop==1
- Description: mixing_beta for densty matrix in each iteration of the outer-loop
- Default: 1.0
- Type: Real
- Availability: basis_type==lcao_in_pw
- Description: It is used to compensate for divergence points at G=0 in the evaluation of Fock exchange using lcao_in_pw method.
- Default: 0.3
- Type: Real
-
Description: To accelerate the evaluation of four-center integrals (
$ik|jl$ ), the product of atomic orbitals are expanded in the basis of auxiliary basis functions (ABF): $\Phi_{i}\Phi_{j}\sim C^{k}{ij}P{k}$. The size of the ABF (i.e. number of$P_{k}$ ) is reduced using principal component analysis. When a large PCA threshold is used, the number of ABF will be reduced, hence the calculation becomes faster. However, this comes at the cost of computational accuracy. A relatively safe choice of the value is 1e-4. - Default: 1E-4
- Type: Real
-
Description: See also the entry exx_pca_threshold. Smaller components (less than exx_c_threshold) of the
$C^{k}_{ij}$ matrix are neglected to accelerate calculation. The larger the threshold is, the faster the calculation and the lower the accuracy. A relatively safe choice of the value is 1e-4. - Default: 1E-4
- Type: Real
- Description: See also the entry exx_pca_threshold. With the approximation $\Phi_{i}\Phi_{j}\sim C^{k}{ij}P{k}$, the four-center integral in Fock exchange is expressed as $(ik|jl)=\Sigma_{a,b}C^{a}{ij}V{ab}C^{b}{kl}$, where $V{ab}=(P_{a}|P_{b})$ is a double-center integral. Smaller values of the V matrix can be truncated to accelerate calculation. The larger the threshold is, the faster the calculation and the lower the accuracy. A relatively safe choice of the value is 0, i.e. no truncation.
- Default: 1E-1
- Type: Real
-
Description: The Fock exchange can be expressed as
$\Sigma_{k,l}(ik|jl)D_{kl}$ where D is the density matrix. Smaller values of the density matrix can be truncated to accelerate calculation. The larger the threshold is, the faster the calculation and the lower the accuracy. A relatively safe choice of the value is 1e-4. - Default: 1E-4
- Type: Real
- Description: See also the entry exx_pca_threshold. $\nabla C^{k}{ij}$ is used in force and stress. Smaller components (less than exx_c_grad_threshold) of the $\nabla C^{k}{ij}$ matrix are neglected to accelerate calculation. The larger the threshold is, the faster the calculation and the lower the accuracy. A relatively safe choice of the value is 1e-4.
- Default: 1E-4
- Type: Real
-
Description: See also the entry exx_pca_threshold. With the approximation $\Phi_{i}\Phi_{j}\sim C^{k}{ij}P{k}$, the four-center integral in Fock exchange is expressed as $(ik|jl)=\Sigma_{a,b}C^{a}{ij}V{ab}C^{b}{kl}$, where $V{ab}=(P_{a}|P_{b})$ is a double-center integral.
$\nabla V_{ab}$ is used in force and stress. Smaller values of the V matrix can be truncated to accelerate calculation. The larger the threshold is, the faster the calculation and the lower the accuracy. A relatively safe choice of the value is 0, i.e. no truncation. - Default: 1E-1
- Type: Real
- Description: In practice the four-center integrals are sparse, and using Cauchy-Schwartz inequality, we can find an upper bound of each integral before carrying out explicit evaluations. Those that are smaller than exx_schwarz_threshold will be truncated. The larger the threshold is, the faster the calculation and the lower the accuracy. A relatively safe choice of the value is 1e-5. (Currently not used)
- Default: 0
- Type: Real
- Description: In practice the Fock exchange matrix is sparse, and using Cauchy-Schwartz inequality, we can find an upper bound of each matrix element before carrying out explicit evaluations. Those that are smaller than exx_cauchy_threshold will be truncated. The larger the threshold is, the faster the calculation and the lower the accuracy. A relatively safe choice of the value is 1e-7.
- Default: 1E-7
- Type: Real
- Description: In practice the Fock exchange matrix in force is sparse, and using Cauchy-Schwartz inequality, we can find an upper bound of each matrix element before carrying out explicit evaluations. Those that are smaller than exx_cauchy_force_threshold will be truncated. The larger the threshold is, the faster the calculation and the lower the accuracy. A relatively safe choice of the value is 1e-7.
- Default: 1E-7
- Type: Real
- Description: In practice the Fock exchange matrix in stress is sparse, and using Cauchy-Schwartz inequality, we can find an upper bound of each matrix element before carrying out explicit evaluations. Those that are smaller than exx_cauchy_stress_threshold will be truncated. The larger the threshold is, the faster the calculation and the lower the accuracy. A relatively safe choice of the value is 1e-7.
- Default: 1E-7
- Type: Real
- Description: It is related to the cutoff of on-site Coulomb potentials. (Currently not used)
- Default: 1e-8
- Type: Real
- Description: This parameter determines how many times larger the radial mesh required for calculating Columb potential is to that of atomic orbitals. For HSE, setting it to 1 is enough. But for PBE0, a much larger number must be used.
- Default:
- 1.5: if dft_functional==hse
- 5: else
- Type: String
- Description: When running in parallel, the evaluation of Fock exchange is done by distributing atom pairs on different processes, then gather the results. exx_distribute_type governs the mechanism of distribution. Available options are
htime
,order
,kmean1
andkmeans2
.order
: Atom pairs are simply distributed by their orders.htime
: The balance in time is achieved on each processor, hence if the memory is sufficient, this is the recommended method.kmeans1
,kmeans2
: Two methods where the k-means clustering method is used to reduce memory requirement. They might be necessary for very large systems. (Currently not used)
- Default:
htime
- Type: Integer
- Availability: dft_functional==opt_orb
- Description: The maximum l of the spherical Bessel functions, when the radial part of opt-ABFs are generated as linear combinations of spherical Bessel functions. A reasonable choice is 2.
- Default: 0
- Type: Real
- Availability: dft_functional==opt_orb
- Description: The cut-off of plane wave expansion, when the plane wave basis is used to optimize the radial ABFs. A reasonable choice is 60.
- Default: 0
- Unit: Ry
- Type: Real
- Availability: dft_functional==opt_orb
- Description: The threshold when solving for the zeros of spherical Bessel functions. A reasonable choice is 1e-12.
- Default: 0
- Type: Boolean
- Description:
- True: Enforce LibRI to use
double
data type. - False: Enforce LibRI to use
complex
data type.
- True: Enforce LibRI to use
- Default: depends on the gamma_only option
- True: if gamma_only
- False: else
- Type: Real
- Description: How many times larger the radial mesh required is to that of atomic orbitals in the postprocess calculation of the bare Coulomb matrix for RPA, GW, etc.
- Default: 10
These variables are used to control molecular dynamics calculations. For more information, please refer to md.md in detail.
-
Type: String
-
Description: Control the algorithm to integrate the equation of motion for molecular dynamics (MD), see md.md in detail.
- fire: a MD-based relaxation algorithm, named fast inertial relaxation engine.
- nve: NVE ensemble with velocity Verlet algorithm.
- nvt: NVT ensemble, see md_thermostat in detail.
- npt: Nose-Hoover style NPT ensemble, see md_pmode in detail.
- langevin: NVT ensemble with Langevin thermostat, see md_damp in detail.
- msst: MSST method, see msst_direction, msst_vel, msst_qmass, msst_vis, msst_tscale in detail.
-
Default: nvt
- Type: Integer
- Description: The total number of molecular dynamics steps.
- Default: 10
- Type: Real
- Description: The time step used in molecular dynamics calculations.
- Default: 1.0
- Unit: fs
-
Type: String
-
Description: Specify the temperature control method used in NVT ensemble.
- nhc: Nose-Hoover chain, see md_tfreq and md_tchain in detail.
- anderson: Anderson thermostat, see md_nraise in detail.
- berendsen: Berendsen thermostat, see md_nraise in detail.
- rescaling: velocity Rescaling method 1, see md_tolerance in detail.
- rescale_v: velocity Rescaling method 2, see md_nraise in detail.
-
Default: nhc
-
Type: Real
-
Description: The temperature used in molecular dynamics calculations.
If
md_tfirst
is unset or less than zero, init_vel is autoset to betrue
. If init_vel istrue
, the initial temperature will be determined by the velocities read fromSTRU
. In this case, if velocities are unspecified inSTRU
, the initial temperature is set to zero.If
md_tfirst
is set to a positive value and init_vel istrue
simultaneously, please make sure they are consistent, otherwise abacus will exit immediately.Note that
md_tlast
is only used in NVT/NPT simulations. Ifmd_tlast
is unset or less than zero,md_tlast
is set tomd_tfirst
. Ifmd_tlast
is set to be different frommd_tfirst
, ABACUS will automatically change the temperature frommd_tfirst
tomd_tlast
. -
Default: No default
-
Unit: K
- Type: Boolean
-
Description: Control whether to restart molecular dynamics calculations and time-dependent density functional theory calculations.
- True: ABACUS will read in
${read_file_dir}/Restart_md.dat
to determine the current step${md_step}
, then read in the correspondingSTRU_MD_${md_step}
in the folderOUT.$suffix/STRU/
automatically. For tddft, ABACUS will also read inLOWF_K_${kpoint}
of the last step (You need to set out_wfc_lcao=1 and out_app_flag=0 to obtain this file). - False: ABACUS will start molecular dynamics calculations normally from the first step.
- True: ABACUS will read in
- Default: False
- Type: Integer
-
Description: The output frequency of
OUT.${suffix}/Restart_md.dat
and structural files in the directoryOUT.${suffix}/STRIU/
, which are used to restart molecular dynamics calculations, see md_restart in detail. - Default: 5
- Type: Integer
- Description: The output frequency of
OUT.${suffix}/MD_dump
in molecular dynamics calculations, which including the information of lattices and atoms. - Default: 1
- Type: Boolean
- Description: Whether to output atomic forces into the file
OUT.${suffix}/MD_dump
. - Default: True
- Type: Boolean
- Description: Whether to output atomic velocities into the file
OUT.${suffix}/MD_dump
. - Default: True
- Type: Boolean
- Description: Whether to output lattice virials into the file
OUT.${suffix}/MD_dump
. - Default: True
- Type: Integer
- Description: The random seed to initialize random numbers used in molecular dynamics calculations.
- < 0: No srand() function is called.
- >= 0: The function srand(md_seed) is called.
- Default: -1
-
Type: Real
-
Description: Control the frequency of temperature oscillations during the simulation. If it is too large, the temperature will fluctuate violently; if it is too small, the temperature will take a very long time to equilibrate with the atomic system.
Note: It is a system-dependent empirical parameter, ranging from 1/(40*md_dt) to 1/(100*md_dt). An improper choice might lead to the failure of jobs.
-
Default: 1/40/md_dt
-
Unit:
$\mathrm{fs^{-1}}$
- Type: Integer
- Description: Number of thermostats coupled with the particles in the NVT/NPT ensemble based on the Nose-Hoover style non-Hamiltonian equations of motion.
- Default: 1
- Type: String
- Description: Specify the cell fluctuation mode in NPT ensemble based on the Nose-Hoover style non-Hamiltonian equations of motion.
- iso: The three diagonal elements of the lattice are fluctuated isotropically.
- aniso: The three diagonal elements of the lattice are fluctuated anisotropically.
- tri: The lattice must be a lower-triangular matrix, and all six freedoms are fluctuated.
- Default: iso
- Relavent: md_tfreq, md_tchain, md_pcouple, md_pfreq, and md_pchain.
-
Type: Integer
-
Description: Determine the precision level of variable-cell molecular dynamics calculations.
- 0: FFT grids do not change, only G vectors and K vectors are changed due to the change of lattice vector. This level is suitable for cases where the variation of the volume and shape is not large, and the efficiency is relatively higher.
- 2: FFT grids change per step. This level is suitable for cases where the variation of the volume and shape is large, such as the MSST method. However, accuracy comes at the cost of efficiency.
-
Default: 0
- Type: Real
- Description: Construct a reference cell bigger than the initial cell. The reference cell has to be large enough so that the lattice vectors of the fluctuating cell do not exceed the reference lattice vectors during MD. Typically, 1.02 ~ 1.10 is sufficient. However, the cell fluctuations depend on the specific system and thermodynamic conditions. So users must test for a proper choice. This parameters should be used in conjunction with erf_ecut, erf_height, and erf_sigma.
- Default: 1.0
- Type: String
- Description: The coupled lattice vectors will scale proportionally in NPT ensemble based on the Nose-Hoover style non-Hamiltonian equations of motion.
- none: Three lattice vectors scale independently.
- xyz: Lattice vectors x, y, and z scale proportionally.
- xy: Lattice vectors x and y scale proportionally.
- xz: Lattice vectors x and z scale proportionally.
- yz: Lattice vectors y and z scale proportionally.
- Default: none
- Type: Real
- Description: The target pressure used in NPT ensemble simulations, the default value of
md_plast
ismd_pfirst
. Ifmd_plast
is set to be different frommd_pfirst
, ABACUS will automatically change the target pressure frommd_pfirst
tomd_plast
. - Default: -1.0
- Unit: kbar
-
Type: Real
-
Description: The frequency of pressure oscillations during the NPT ensemble simulation. If it is too large, the pressure will fluctuate violently; if it is too small, the pressure will take a very long time to equilibrate with the atomic system.
Note: It is a system-dependent empirical parameter. An improper choice might lead to the failure of jobs.
-
Default: 1/400/md_dt
-
Unit:
$\mathrm{kbar^{-1}}$
- Type: Integer
- Description: The number of thermostats coupled with the barostat in the NPT ensemble based on the Nose-Hoover style non-Hamiltonian equations of motion.
- Default: 1
- Type: Real
- Description: Cut-off radius for Leonard Jones potential.
- Default: 8.5 (for He)
- Unit: Angstrom
- Type: Real
- Description: The value of epsilon for Leonard Jones potential.
- Default: 0.01032 (for He)
- Unit: eV
- Type: Real
- Description: The value of sigma for Leonard Jones potential.
- Default: 3.405 (for He)
- Unit: Angstrom
- Type: String
- Description: The filename of DP potential files, see md.md in detail.
- Default: graph.pb
- Type: Integer
- Description: The direction of the shock wave in the MSST method.
- 0: x direction
- 1: y direction
- 2: z direction
- Default: 2
- Type: Real
- Description: The velocity of the shock wave in the MSST method.
- Default: 0.0
- Unit: Angstrom/fs
- Type: Real
- Description: Artificial viscosity in the MSST method.
- Default: 0.0
- Unit: g/(mol*Angstrom*fs)
- Type: Real
- Description: The reduction percentage of the initial temperature used to compress volume in the MSST method.
- Default: 0.01
- Type: Real
- Description: Inertia of the extended system variable. You should set a number larger than 0.
- Default: No default
-
Unit:
$\mathrm{g^{2}/(mol^{2}*Angstrom^{4})}$
- Type: Real
- Description: The damping parameter used to add fictitious force in the Langevin method.
- Default: 1.0
- Unit: fs
- Type: Real
- Description: Thr temperature tolerance for velocity rescaling. Velocities are rescaled if the current and target temperature differ more than
md_tolerance
. - Default: 100.0
- Unit: K
- Type: Integer
- Description:
- Anderson: The "collision frequency" parameter is given as 1/
md_nraise
. - Berendsen: The "rise time" parameter is given in units of the time step: tau =
md_nraise
*md_dt
, somd_dt
/tau = 1/md_nraise
. - Rescale_v: Every
md_nraise
steps the current temperature is rescaled to the target temperature.
- Anderson: The "collision frequency" parameter is given as 1/
- Default: 1
- Type: Boolean
- Description: Whether the asynchronous overlap matrix is calculated for Hefei-NAMD.
- Default: False
- Type: Real
- Description: The maximum displacement of all atoms in one step. This parameter is useful when cal_syns = True.
- Default: 0.01
- Unit: bohr
These variables are used to control DFT+U correlated parameters
- Type: Integer
- Description: Determines whether to calculate the plus U correction, which is especially important for correlated electrons.
- 1: Calculate plus U correction with radius-adjustable localized projections (with parameter
onsite_radius
). - 2: Calculate plus U correction using first zeta of NAOs as projections (this is old method for testing).
- 0: Do not calculate plus U correction.
- 1: Calculate plus U correction with radius-adjustable localized projections (with parameter
- Default: 0
- Type: Integer
-
Description: Specifies which orbits need plus U correction for each atom type (
$l_1,l_2,l_3,\ldots$ for atom type 1, 2, 3, respectively).- -1: The plus U correction will not be calculated for this atom.
- 1: For p-electron orbits, the plus U correction is needed.
- 2: For d-electron orbits, the plus U correction is needed.
- 3: For f-electron orbits, the plus U correction is needed.
- Default: None
- Type: Real
- Description: Specifies the Hubbard Coulomb interaction parameter U (eV) in plus U correction, which should be specified for each atom unless the Yukawa potential is used.
Note: Since only the simplified scheme by Duradev is implemented, the 'U' here is actually U-effective, which is given by Hubbard U minus Hund J.
- Default: 0.0
- Type: Boolean
- Description: Determines whether to use the local screen Coulomb potential method to calculate the values of U and J.
- True:
hubbard_u
does not need to be specified. - False:
hubbard_u
does need to be specified.
- True:
- Default: False
- Type: Real
- Availability: DFT+U with
yukawa_potential
= True. - Description: The screen length of Yukawa potential. If left to default, the screen length will be calculated as an average of the entire system. It's better to stick to the default setting unless there is a very good reason.
- Default: Calculated on the fly.
- Type: Real
- Unit: eV
- Availability: DFT+U calculations with
mixing_restart > 0
. - Description: Once
uramping
> 0.15 eV. DFT+U calculations will start SCF with U = 0 eV, namely normal LDA/PBE calculations. Once SCF restarts whendrho<mixing_restart
, U value will increase byuramping
eV. SCF will repeat above calcuations until U values reach target defined inhubbard_u
. As foruramping=1.0 eV
, the recommendations ofmixing_restart
is around5e-4
. - Default: -1.0.
- Type: Integer
- Description: The parameter controls the form of occupation matrix control used.
- 0: No occupation matrix control is performed, and the onsite density matrix will be calculated from wavefunctions in each SCF step.
- 1: The first SCF step will use an initial density matrix read from a file named
[initial_onsite.dm](http://initial_onsite.dm/)
, but for later steps, the onsite density matrix will be updated. - 2: The same onsite density matrix from
initial_onsite.dm
will be used throughout the entire calculation.
Note : The easiest way to create
initial_onsite.dm
is to run a DFT+U calculation, look for a file namedonsite.dm
in the OUT.prefix directory, and make replacements there. The format of the file is rather straight-forward.
- Default: 0
-
Type: Real
-
Availability:
dft_plus_u
is set to 1 -
Description:
- The
Onsite-radius
parameter facilitates modulation of the single-zeta portion of numerical atomic orbitals for projections for DFT+U. - The modulation algorithm includes a smooth truncation applied directly to the tail of the original orbital, followed by normalization. Consider the function: $$ g(r;\sigma)=\begin{cases} 1-\exp\left(-\frac{(r-r_c)^2}{2\sigma^2}\right), & r < r_c\ 0, & r \geq r_c \end{cases} $$
- where
$\sigma$ is a parameter that controls the smoothing interval. A normalized function truncated smoothly at$r_c$ can be represented as:
$$ \alpha(r) = \frac{\chi(r)g(r;\sigma)}{\langle\chi(r)g(r;\sigma), \chi(r)g(r;\sigma)\rangle} $$
-
To find an appropriate
$\sigma$ , the optimization process is as follows: -
Maximizing the overlap integral under a normalization constraint is equivalent to minimizing an error function:
$$ \min \langle \chi(r)-\alpha(r), \chi(r)-\alpha(r)\rangle \quad \text{subject to} \quad \langle \alpha(r),\alpha(r)\rangle=1 $$
- Similar to the process of generating numerical atomic orbitals, this optimization choice often induces additional oscillations in the outcome. To suppress these oscillations, we may include a derivative term in the objective function (
$f'(r)\equiv \mathrm{d}f(r)/\mathrm{d}r$ ):
$$ \min \left[\gamma\langle \chi(r)-\alpha(r), \chi(r)-\alpha(r)\rangle + \langle \chi'(r)-\alpha'(r), \chi'(r)-\alpha'(r)\rangle\right] \quad \text{subject to} \quad \langle \alpha(r),\alpha(r)\rangle=1 $$
- where
$\gamma$ is a parameter that adjusts the relative weight of the error function to the derivative error function.
- The
-
Unit: Bohr
-
Default: 5.0
These variables are used to control vdW-corrected related parameters.
- Type: String
- Description: Specifies the method used for Van der Waals (VdW) correction. Available options are:
d2
: Grimme's D2 dispersion correction methodd3_0
: Grimme's DFT-D3(0) dispersion correction methodd3_bj
: Grimme's DFTD3(BJ) dispersion correction methodnone
: no vdW correction
- Default: none
- Type: Real
- Availability:
vdw_method
is set tod2
,d3_0
, ord3_bj
- Description: This scale factor is used to optimize the interaction energy deviations in van der Waals (vdW) corrected calculations. The recommended values of this parameter are dependent on the chosen vdW correction method and the DFT functional being used. For DFT-D2, the recommended values are 0.75 (PBE), 1.2 (BLYP), 1.05 (B-P86), 1.0 (TPSS), and 1.05 (B3LYP). For DFT-D3, recommended values with different DFT functionals can be found on the here. The default value of this parameter in ABACUS is set to be the recommended value for PBE.
- Default:
- 0.75: if
vdw_method
is set tod2
- 1.0: if
vdw_method
is set tod3_0
ord3_bj
- 0.75: if
- Type: Real
- Availability:
vdw_method
is set tod3_0
ord3_bj
- Description: This scale factor is relevant for D3(0) and D3(BJ) van der Waals (vdW) correction methods. The recommended values of this parameter with different DFT functionals can be found on the webpage. The default value of this parameter in ABACUS is set to be the recommended value for PBE.
- Default:
- 0.722: if
vdw_method
is set tod3_0
- 0.7875: if
vdw_method
is set tod3_bj
- 0.722: if
- Type: Real
- Availability:
vdw_method
is set tod3_0
ord3_bj
- Description: This damping function parameter is relevant for D3(0) and D3(BJ) van der Waals (vdW) correction methods. The recommended values of this parameter with different DFT functionals can be found on the webpage. The default value of this parameter in ABACUS is set to be the recommended value for PBE.
- Default:
- 1.217: if
vdw_method
is set tod3_0
- 0.4289: if
vdw_method
is set tod3_bj
- 1.217: if
- Type: Real
- Availability:
vdw_method
is set tod3_0
ord3_bj
- Description: This damping function parameter is only relevant for D3(0) and D3(BJ) van der Waals (vdW) correction methods. The recommended values of this parameter with different DFT functionals can be found on the webpage. The default value of this parameter in ABACUS is set to be the recommended value for PBE.
- Default:
- 1.0: if
vdw_method
is set tod3_0
- 4.4407: if
vdw_method
is set tod3_bj
- 1.0: if
- Type: Real
- Availability:
vdw_method
is set tod2
- Description: Controls the damping rate of the damping function in the DFT-D2 method.
- Default: 20
- Type: Integer
- Availability:
vdw_method
is set tod3_0
ord3_bj
- Description: Determines whether three-body terms are calculated for DFT-D3 methods.
- True: ABACUS will calculate the three-body term.
- False: The three-body term is not included.
- Default: False
-
Type: String
-
Availability:
vdw_method
is set tod2
-
Description: Specifies the name of the file containing
$C_6$ parameters for each element when using the D2 method. If not set, ABACUS uses the default$C_6$ parameters (Jnm6/mol) stored in the program. To manually set the$C_6$ parameters, provide a file containing the parameters. An example is given by:H 0.1 Si 9.0
Namely, each line contains the element name and the corresponding
$C_6$ parameter. -
Default: default
- Type: String
-
Availability:
vdw_C6_file
is not default -
Description: Specifies the unit of the provided
$C_6$ parameters in the D2 method. Available options are:-
Jnm6/mol
(J·nm^6/mol) -
eVA
(eV·Angstrom)
-
- Default: Jnm6/mol
-
Type: String
-
Availability:
vdw_method
is set tod2
-
Description: Specifies the name of the file containing
$R_0$ parameters for each element when using the D2 method. If not set, ABACUS uses the default$R_0$ parameters (Angstrom) stored in the program. To manually set the$R_0$ parameters, provide a file containing the parameters. An example is given by:Li 1.0 Cl 2.0
Namely, each line contains the element name and the corresponding
$R_0$ parameter. -
Default: default
- Type: String
-
Availability:
vdw_R0_file
is not default -
Description: Specifies the unit for the
$R_0$ parameters in the D2 method when manually set by the user. Available options are:-
A
(Angstrom) Bohr
-
- Default: A
- Type: String
- Description: Determines the method used for specifying the cutoff radius in periodic systems when applying Van der Waals correction. Available options are:
radius
: The supercell is selected within a sphere centered at the origin with a radius defined byvdw_cutoff_radius
.period
: The extent of the supercell is explicitly specified using thevdw_cutoff_period
keyword.
- Default: radius
- Type: Real
- Availability:
vdw_cutoff_type
is set toradius
- Description: Defines the radius of the cutoff sphere when
vdw_cutoff_type
is set toradius
. The default values depend on the chosenvdw_method
. - Default:
- 56.6918 if
vdw_method
is set tod2
- 95 if
vdw_method
is set tod3_0
ord3_bj
- 56.6918 if
- Unit: defined by
vdw_radius_unit
(defaultBohr
)
- Type: String
- Availability:
vdw_cutoff_type
is set toradius
- Description: specify the unit of
vdw_cutoff_radius
. Available options are:A
(Angstrom)Bohr
- Default: Bohr
- Type: Integer Integer Integer
- Availability:
vdw_cutoff_type
is set toperiod
- Description: The three integers supplied here explicitly specify the extent of the supercell in the directions of the three basis lattice vectors.
- Default: 3 3 3
- Type: Real
- Availability:
vdw_method
is set tod3_0
ord3_bj
- Description: The cutoff radius when calculating coordination numbers.
- Default: 40
- Unit: defined by
vdw_cn_thr_unit
(default:Bohr
)
- Type: String
- Description: Unit of the coordination number cutoff (
vdw_cn_thr
). Available options are:A
(Angstrom)Bohr
- Default: Bohr
These variables are used to control berry phase and wannier90 interface parameters. Detail introduce
- Type: Boolean
- Description: controls the calculation of Berry phase
- true: Calculate Berry phase.
- false: Do not calculate Berry phase.
- Default: false
- Type: Integer
- Description: the direction of the polarization in the lattice vector for Berry phase calculation
- 1: Calculate the polarization in the direction of the lattice vector a_1 defined in the STRU file.
- 2: Calculate the polarization in the direction of the lattice vector a_2 defined in the STRU file.
- 3: Calculate the polarization in the direction of the lattice vector a_3 defined in the STRU file.
- Default: 3
- Type: Integer
- Description: Controls the generation of files for the Wannier90 code.
- 1: Generate files for the Wannier90 code.
- 0: Do not generate files for the Wannier90 code.
- Default: 0
- Type: String
- Description: the file name generated when running "wannier90 -pp ..." command
- Default: seedname.nnkp
- Type: Integer
- Description: Only available on LCAO basis, using different methods to generate "*.mmn" file and "*.amn" file.
- 1: Calculated using the
lcao_in_pw
method, the calculation accuracy can be improved by increasingecutwfc
to maintain consistency with the pw basis set results. - 2: The overlap between atomic orbitals is calculated using grid integration. The radial grid points are generated using the Gauss-Legendre method, while the spherical grid points are generated using the Lebedev-Laikov method.
- 1: Calculated using the
- Default: 1
- Type: String
- Description: the spin direction for the Wannier function calculation when nspin is set to 2
up
: Calculate spin up for the Wannier function.down
: Calculate spin down for the Wannier function.
- Default:
up
- Type: Bool
- Description: write the "*.mmn" file or not.
- 0: don't write the "*.mmn" file.
- 1: write the "*.mmn" file.
- Default: 1
- Type: Bool
- Description: write the "*.amn" file or not.
- 0: don't write the "*.amn" file.
- 1: write the "*.amn" file.
- Default: 1
- Type: Bool
- Description: write the "*.eig" file or not.
- 0: don't write the "*.eig" file.
- 1: write the "*.eig" file.
- Default: 1
- Type: Bool
- Description: write the "UNK.*" file or not.
- 0: don't write the "UNK.*" file.
- 1: write the "UNK.*" file.
- Default: 0
- Type: Bool
- Description: write the "UNK.*" file in ASCII format or binary format.
- 0: write the "UNK.*" file in binary format.
- 1: write the "UNK.*" file in ASCII format (text file format).
- Default: 1
- Type: Integer
- Description: the method to calculate the energy density matrix
- 0: new method (use the original formula).
- 1: old method (use the formula for ground state).
- Default: 0
- Type: Real
-
Description:
- <0: don't print
$E_{ij}$ . - >=0: print the
$E_{ij}\ (<\psi_i|H|\psi_j>$ ) elements which are larger than td_print_eij.
- <0: don't print
- Default: -1
- Type: Integer
- Description:
method of propagator
- 0: Crank-Nicolson.
- 1: 4th Taylor expansions of exponential.
- 2: enforced time-reversal symmetry (ETRS).
- Default: 0
- Type: Boolean
- Description:
- True: add a laser material interaction (extern laser field).
- False: no extern laser field.
- Default: False
- Type: String
- Description:
If
td_vext
is True, the td_vext_dire is a string to set the number of electric fields, liketd_vext_dire 1 2
representing external electric field is added to the x and y axis at the same time. Parameters of electric field can also be written as a string, liketd_gauss_phase 0 1.5707963267948966
representing the Gauss field in the x and y directions has a phase delay of Pi/2. See below for more parameters of electric field.- 1: the direction of external light field is along x axis.
- 2: the direction of external light field is along y axis.
- 3: the direction of external light field is along z axis.
- Default: 1
- Type: Integer
- Description:
type of electric field in space domain
- 0: length gauge.
- 1: velocity gauge.
- Default: 0
- Type: Integer
- Description:
type of electric field in time domain
- 0: Gaussian type function.
- 1: Trapezoid function.
- 2: Trigonometric function.
- 3: Heaviside function.
- 4: HHG function.
- Default: 0
- Type: Integer
- Description: number of steps where electric field starts
- Default: 1
- Type: Integer
- Description: number of steps where electric field ends
- Default: 100
- Type: Real
- Description:
cut1 of interval in length gauge
E = E0 , cut1<x<cut2
E = -E0/(cut1+1-cut2) , x<cut1 or cut2<x<1 - Default: 0.05
- Type: Real
- Description:
cut2 of interval in length gauge
E = E0 , cut1<x<cut2
E = -E0/(cut1+1-cut2) , x<cut1 or cut2<x<1 - Default: 0.05
- Type: Real
- Description:
frequency (freq) of Gauss type electric field (fs^-1)
amp*cos(2pi*freq(t-t0)+phase)exp(-(t-t0)^2/2sigma^2) - Default: 22.13
- Type: Real
- Description:
phase of Gauss type electric field
amp*(2pi*freq(t-t0)+phase)exp(-(t-t0)^2/2sigma^2) - Default: 0.0
- Type: Real
- Description:
sigma of Gauss type electric field (fs)
amp*cos(2pi*freq(t-t0)+phase)exp(-(t-t0)^2/2sigma^2) - Default: 30.0
- Type: Real
- Description:
step number of time center (t0) of Gauss type electric field
amp*cos(2pi*freq(t-t0)+phase)exp(-(t-t0)^2/2sigma^2) - Default: 100
- Type: Real
- Description:
amplitude (amp) of Gauss type electric field (V/Angstrom)
amp*cos(2pi*freq(t-t0)+phase)exp(-(t-t0)^2/2sigma^2) - Default: 0.25
- Type: Real
- Description:
frequency (freq) of Trapezoid type electric field (fs^-1)
E = amp*cos(2pi*freq*t+phase) t/t1 , t<t1
E = amp*cos(2pi*freq*t+phase) , t1<t<t2
E = amp*cos(2pi*freq*t+phase) (1-(t-t2)/(t3-t2)) , t2<t<t3
E = 0 , t>t3 - Default: 1.60
- Type: Real
- Description:
phase of Trapezoid type electric field
E = amp*cos(2pi*freq*t+phase) t/t1 , t<t1
E = amp*cos(2pi*freq*t+phase) , t1<t<t2
E = amp*cos(2pi*freq*t+phase) (1-(t-t2)/(t3-t2)) , t2<t<t3
E = 0 , t>t3 - Default: 0.0
- Type: Real
- Description:
step number of time interval 1 (t1) of Trapezoid type electric field
E = amp*cos(2pi*freq*t+phase) t/t1 , t<t1
E = amp*cos(2pi*freq*t+phase) , t1<t<t2
E = amp*cos(2pi*freq*t+phase) (1-(t-t2)/(t3-t2)) , t2<t<t3
E = 0 , t>t3 - Default: 1875
- Type: Real
- Description:
step number of time interval 2 (t2) of Trapezoid type electric field
E = amp*cos(2pi*freq*t+phase) t/t1 , t<t1
E = amp*cos(2pi*freq*t+phase) , t1<t<t2
E = amp*cos(2pi*freq*t+phase) (1-(t-t2)/(t3-t2)) , t2<t<t3
E = 0 , t>t3 - Default: 5625
- Type: Real
- Description:
step number of time interval 3 (t3) of Trapezoid type electric field
E = amp*cos(2pi*freq*t+phase) t/t1 , t<t1
E = amp*cos(2pi*freq*t+phase) , t1<t<t2
E = amp*cos(2pi*freq*t+phase) (1-(t-t2)/(t3-t2)) , t2<t<t3
E = 0 , t>t3 - Default: 7500
- Type: Real
- Description:
amplitude (amp) of Trapezoid type electric field (V/Angstrom)
E = amp*cos(2pi*freq*t+phase) t/t1 , t<t1
E = amp*cos(2pi*freq*t+phase) , t1<t<t2
E = amp*cos(2pi*freq*t+phase) (1-(t-t2)/(t3-t2)) , t2<t<t3
E = 0 , t>t3 - Default: 2.74
- Type: Real
- Description:
frequency 1 (freq1) of Trigonometric type electric field (fs^-1)
amp*cos(2*pi*freq1*t+phase1)*sin(2*pi*freq2*t+phase2)^2 - Default: 1.164656
- Type: Real
- Description:
frequency 2 (freq2) of Trigonometric type electric field (fs^-1)
amp*cos(2*pi*freq1*t+phase1)*sin(2*pi*freq2*t+phase2)^2 - Default: 0.029116
- Type:Real
- Description:
phase 1 (phase1) of Trigonometric type electric field
amp*cos(2*pi*freq1*t+phase1)*sin(2*pi*freq2*t+phase2)^2 - Default: 0.0
- Type: Real
- Description:
phase 2 (phase2) of Trigonometric type electric field
amp*cos(2*pi*freq1*t+phase1)*sin(2*pi*freq2*t+phase2)^2 - Default: 0.0
- Type: Real
- Description:
amplitude (amp) of Trigonometric type electric field (V/Angstrom)
amp*cos(2*pi*freq1*t+phase1)*sin(2*pi*freq2*t+phase2)^2 - Default: 2.74
- Type: Real
- Description:
step number of switch time (t0) of Heaviside type electric field
E = amp , t<t0
E = 0.0 , t>t0 - Default: 100
- Type: Real
- Description:
amplitude (amp) of Heaviside type electric field (V/Angstrom)
E = amp , t<t0
E = 0.0 , t>t0 - Default: 2.74
- Type: Boolean
- Description:
- True: output dipole.
- False: do not output dipole.
- Default: False
- Type: Boolean
- Description: output TDDFT Efield or not(V/Angstrom)
- True: output efield.
- False: do not output efield.
- Default: False
- Type: Boolean
- Availability:
- For PW and LCAO codes. if set to 1, occupations of bands will be setting of "ocp_set".
- For TDDFT in LCAO codes. if set to 1, occupations will be constrained since second ionic step.
- For OFDFT, this feature can't be used.
- Description:
- True: fix the occupations of bands.
- False: do not fix the occupations of bands.
- Default: False
- Type: String
- Description: If ocp is True, the ocp_set is a string to set the number of occupancy, like '1 10 * 1 0 1' representing the 13 band occupancy, 12th band occupancy 0 and the rest 1, the code is parsing this string into an array through a regular expression.
- Default: none
- Type: Boolean
- Description: Specify whether to include kinetic term in obtaining the Hamiltonian matrix.
- 0: No.
- 1: Yes.
- Default: 1
- Type: Boolean
- Description: Specify whether to include local pseudopotential term in obtaining the Hamiltonian matrix.
- 0: No.
- 1: Yes.
- Default: 1
- Type: Boolean
- Description: Specify whether to include non-local pseudopotential term in obtaining the Hamiltonian matrix.
- 0: No.
- 1: Yes.
- Default: 1
- Type: Boolean
- Description: Specify whether to include Hartree potential term in obtaining the Hamiltonian matrix.
- 0: No.
- 1: Yes.
- Default: 1
- Type: Boolean
- Description: Specify whether to include local ionic potential term in obtaining the Hamiltonian matrix.
- 0: No.
- 1: Yes.
- Default: 1
- Type: Boolean
- Description: Specify whether to output the detailed components in forces.
- 0: No.
- 1: Yes.
- Default: 0
- Type: Boolean
- Description: Specify whether to output the detailed components in stress.
- 0: No.
- 1: Yes.
- Default: 0
- Type: Boolean
- Description: Specify whether to set the colorful output in terminal.
- 0: No.
- 1: Yes.
- Default: 0
- Type: Boolean
- Description: Specify whether to skip the calculation of the ewald energy.
- 0: No.
- 1: Yes.
- Default: 0
Frequency-dependent electronic conductivities can be calculated with Kubo-Greenwood formula [Phys. Rev. B 83, 235120 (2011)].
Onsager coefficients:
They can also be computed by
$L_{mn}=\frac{2e^{m+n-2}}{3\Omega\hbar\omega}\Im[\tilde{C}{mn}(\omega)]$ Guassian smearing: $\tilde{C}{mn}=\int_0^\infty C_{mn}(t)e^{-i\omega t}e^{-\frac{1}{2}s^2t^2}dt$ Lorentzian smearing: $\tilde{C}{mn}=\int_0^\infty C{mn}(t)e^{-i\omega t}e^{-\gamma t}dt$
where
Frequency-dependent electric conductivities:
Frequency-dependent thermal conductivities:
DC electric conductivities:
Thermal conductivities:
- Type: Boolean
- Availability: basis_type =
pw
- Description: Whether to calculate electronic conductivities.
- Default: False
- Type: Real
- Availability: esolver_type =
sdft
- Description: Control the error of Chebyshev expansions for conductivities.
- Default: 1e-8
- Type: Real
-
Availability: basis_type =
pw
-
Description: Frequency interval (
$\mathrm{d}\omega$ ) for frequency-dependent conductivities. - Default: 0.1
- Unit: eV
- Type: Real
- Availability: basis_type =
pw
- Description: Cutoff frequency for frequency-dependent conductivities.
- Default: 10.0
- Unit: eV
- Type: Real
-
Availability: basis_type =
pw
-
Description: Time interval (
$\mathrm{d}t$ ) to integrate Onsager coefficients. - Default: 0.02
- Unit: a.u.
- Type: Integer
- Availability: esolver_type =
sdft
- Description: exp(iH*dt*cond_dtbatch) is expanded with Chebyshev expansion to calculate conductivities. It is faster but costs more memory.
- If
cond_dtbatch = 0
: Autoset this parameter to make expansion orders larger than 100.
- If
- Default: 0
- Type: Integer
- Description: Smearing method for conductivities
- 1: Gaussian smearing
- 2: Lorentzian smearing
- Default: 1
- Type: Real
-
Availability: basis_type =
pw
-
Description: FWHM for conductivities. For Gaussian smearing,
$\mathrm{FWHM}=2\sqrt{2\ln2}s$ ; for Lorentzian smearing,$\mathrm{FWHM}=2\gamma$ . - Default: 0.4
- Unit: eV
- Type: Boolean
-
Availability: basis_type =
pw
-
Description: Whether to consider nonlocal potential correction when calculating velocity matrix
$\bra{\psi_i}\hat{v}\ket{\psi_j}$ .- True:
$m\hat{v}=\hat{p}+\frac{im}{\hbar}[\hat{V}_{NL},\hat{r}]$ . - False:
$m\hat{v}\approx\hat{p}$ .
- True:
- Default: True
These variables are used to control the usage of implicit solvation model. This approach treats the solvent as a continuous medium instead of individual "explicit" solvent molecules, which means that the solute is embedded in an implicit solvent and the average over the solvent degrees of freedom becomes implicit in the properties of the solvent bath.
- Type: Boolean
- Description: calculate implicit solvation correction
- Default: False
- Type: Real
- Availability:
imp_sol
is true. - Description: the relative permittivity of the bulk solvent, 80 for water
- Default: 80
- Type: Real
- Description: The effective surface tension parameter that describes the cavitation, the dispersion, and the repulsion interaction between the solute and the solvent which are not captured by the electrostatic terms
- Default: 1.0798e-05
-
Unit:
$Ry/Bohr^{2}$
- Type: Real
- Description: the width of the diffuse cavity that is implicitly determined by the electronic structure of the solute
- Default: 0.6
- Type: Real
- Description: the value of the electron density at which the dielectric cavity forms
- Default: 0.00037
-
Unit:
$Bohr^{-3}$
These variables are used to control the usage of QO analysis. QO further compress information from LCAO: usually PW basis has dimension in million, LCAO basis has dimension below thousand, and QO basis has dimension below hundred.
- Type: Boolean
- Description: whether to let ABACUS output QO analysis required files
- Default: 0
-
Type: String
-
Description: specify the type of atomic basis
pswfc
: use the pseudowavefunction in pseudopotential files as atomic basis. To use this option, please make sure in pseudopotential file there is pswfc in it.hydrogen
: generate hydrogen-like atomic basis (or with Slater screening).szv
: use the first set of zeta for each angular momentum from numerical atomic orbitals as atomic basis.
warning: to use
pswfc
, please use norm-conserving pseudopotentials with pseudowavefunctions, SG15 pseudopotentials cannot support this option. Developer notes: for ABACUS-lcao calculation, it is the most recommend to useszv
instead ofpswfc
which is originally put forward in work of QO implementation on PW basis. The information loss always happens ifpswfc
orhydrogen
orbitals are not well tuned, although making kpoints sampling more dense will mitigate this problem, but orbital-adjust parameters are needed to test system-by-system in this case. -
Default:
szv
-
Type: String [String...](optional)
-
Description: specify the strategy to generate radial orbitals for each atom type. If one parameter is given, will apply to all atom types. If more than one parameters are given but fewer than number of atom type, those unspecified atom type will use default value.
For
qo_basis hydrogen
-
minimal-nodeless
: according to principle quantum number of the highest occupied state, generate only nodeless orbitals, for example Cu, only generate 1s, 2p, 3d and 4f orbitals (for Cu, 4s is occupied, thus$n_{max} = 4$ ) -
minimal-valence
: according to principle quantum number of the highest occupied state, generate only orbitals with highest principle quantum number, for example Cu, only generate 4s, 4p, 4d and 4f orbitals. -
full
: similarly according to the maximal principle quantum number, generate all possible orbitals, therefore for Cu, for example, will generate 1s, 2s, 2p, 3s, 3p, 3d, 4s, 4p, 4d, 4f. -
energy-full
: will generate hydrogen-like orbitals according to Aufbau principle. For example the Cu (1s2 2s2 2p6 3s2 3p6 3d10 4s1), will generate these orbitals. -
energy-valence
: from the highest n (principal quantum number) layer and n-1 layer, generate all occupied and possible ls (angular momentum quantum number) for only once, for example Cu, will generate 4s, 3d and 3p orbitals.
For
qo_basis pswfc
andqo_basis szv
-
all
: use all possible pseudowavefunctions/numerical atomic orbital (of first zeta) in pseudopotential/numerical atomic orbital file. -
s
/p
/d
/...: only use s/p/d/f/...-orbital(s). -
spd
: use s, p and d orbital(s). Any unordered combination is acceptable.
warning: for
qo_basis hydrogen
to usefull
, generation strategy may cause the space spanned larger than the one spanned by numerical atomic orbitals, in this case, must filter out orbitals in some way -
-
Default: for
hydrogen
:energy-valence
, forpswfc
andszv
:all
-
Type: Real [Real...](optional)
-
Description: rescale the shape of radial orbitals, available for both
qo_basis hydrogen
andqo_basis pswfc
. cases but has different meaning.For
qo_basis pswfc
For each atom type, screening factor$e^{-\eta|\mathbf{r}|}$ is multiplied to the pswfc to mimic the behavior of some kind of electron.$\eta$ is the screening coefficient. If only one value is given, then will apply to each atom type. If not enough values are given, will apply default value to rest of atom types. This parameter plays important role in controlling the spread of QO orbitals together withqo_thr
.For
qo_basis hydrogen
If any float number is given, will apply Slater screening to all atom types. Slater screening is a classic and empirical method roughly taking many-electron effect into account for obtaining more accurate results when evaluating electron affinity and ionization energy. The Coulomb potential then becomes$V(r) = -\frac{Z-\sigma}{r}$ . For example the effective nuclear charge for Cu 3d electrons now reduces from 29 to 7.85, 4s from 29 to 3.70, which means Slater screening will bring about longer tailing effect. If no value is given, will not apply Slater screening. -
Default: 0.1
-
Unit: Bohr^-1
- Type: Real
- Description: the convergence threshold determining the cutoff of generated orbital. Lower threshold will yield orbital with larger cutoff radius.
- Default: 1.0e-6