PySCF v1.3 release
New features:
- Spin-free X2C Hamiltonian for PBC calculation
- Overlap of two CI wavefunctions over different orbital bases
- EOM-CCSD for user guess, Koopmans' excitations, etc
- Approximate EOM-CCSD (MBPT2 ground state and partitioned EOM Hbar)
- AVAS method for constructing CASSCF active space
- Molpro XML file reader and interface to read Molpro orbitals
- Supports for 1D, 2D PBC systems
- Quantum chemistry ECP for crystalline system
- AO-driven CCSD
- UCCSD
- CI coefficients transformation for one-particle basis rotation
- CIAH second order SCF solver for PBC KRHF and KUHF methods
- CISD and CISD 1, 2-particle density matrices
- Selected-CI and Selected-CI 1, 2-particle density matrices
- Smearing for PBC mean-field calculation
- Density fitting (with Gaussian as auxiliary basis) for crystalline systems
Improvements:
- Performance of CCSD(T)
- The default kpts mesh (to always include gamma point)
- Treatment of auxiliary basis linear dependence in PBC DF/MDF module
- Atomic grids in PBC DFT calculation
- Cutoff radius in real space lattice summation for better accuracy
- EOM-EE-RCCSD and EOM-EE-UCCSD performance
- Memory usage of the non-symmetric Davidson solver in EOM-CCSD
- Integral transformation for PBC 2-electron integrals
- CASSCF state-average interface to handle sub-solvers of different spins
- Numerical stability for Davidson diagonalization solver
- Numerical stability of FCI contraction function under multi-threading environment
- Performance of FCI 2-electron contraction function with point group symmetry