v1.6.0

• New Features (PBC systems)
  • Analytical nuclear gradients for periodic density-fitting methods.
  • Constrained DFT (CDFT) SCF and nuclear gradient support.
• New Features (molecular systems)
  • C6 coefficient calculation via Casimir-Polder integration (#619)
  • Unrestricted KS vv10 gradient and hessian (#640)
  • Constrained DFT (CDFT) SCF and nuclear gradients
  • Function to compute grid density with density gradient and tau (#659)
  • Density-Fitting MP2 (#662)
  • Fewest-switches surface hopping (FSSH) non-adiabatic dynamics with TDDFT.
• Improvements (PBC systems)
  • Performance optimizations for 2c2e integrals and their derivatives.
  • The default numerical precision for one-center overlap and kinetic integrals under PBC.
  • Accelerated Becke weight evaluation.
  • Added support for disabling radii adjustment in Becke derivative kernels.
  • Support for Becke grid derivatives under PBC.
  • PySCF Mole and Cell class counterparts, with a new from_cpu method for CPU to GPU conversion.
  • multigrid_v2 is now the default integrator (#656).
• Improvements (molecular systems)
  • Refactored derivative integrals of the J and K terms in density-fitting methods, improving performance.
  • Improved efficiency of derivative integral evaluation for TDDFT gradients and NACVs.
  • Optimized CUDA kernels for derivative integrals (#627).
  • Refactored the libxc interface and removed rarely used XC functionals (#635).
  • Upgraded pyscf/dispersion and made gpu4pyscf self-contained with respect to dispersion implementations (#657).
  • Canonical orthogonalization added to the SCF eigenvalue solver.
  • Basis-set linear dependency detection and removal enabled by default.
• Fixes
  • Fixed an issue where the lebedev_order attribute in the SMD module was not recognized.
  • Handle zero strides for cutensor (fix #614)
  • Fix grid dimension overflow bug in ft_ao in fftdf pseudopotential evaluation (#626)
  • Fix a bug that get_rho() provides wrong result if dm has no attached mo_coeff fields (#654)
• API updates
  • Removed the get_veff method from gradient classes.