Supported Use and Limitations

The following conditions apply to the documented backend, feature, and property interfaces in this release.

  • CiderPress supports the classic GPAW calculator. The gpaw.new interface is not implemented in this release.

  • The supported periodic CIDER26XC route is plane-wave mode with PAW setups. PAW supplies the all-electron information needed by its nonlocal features.

  • GPAW implements version-j NLDF models. CIDER24X SDMX models use PySCF.

  • CIDER24X requires PyTorch and is evaluated through PySCF. Periodic PySCF SDMX support is intended primarily for methodological reproduction of the CIDER24X work. [1] Periodic PySCF calculations with SDMX use pseudopotentials and uniform grids. Do not use all-electron setups or atom-centered grids for periodic SDMX calculations in PySCF.

  • CIDER26XCCHEMD4 uses the PySCF interface. Its total energy and analytical molecular gradient both include the D4 correction. CiderPress raises an error for gradients when a model requests the unsupported D3 or nonlocal- correlation post-density modes.

  • The PySCF CIDER decorator provides SCF energies and the gradients listed in Energies and Derivative Properties. Hessians, NMR, polarizability, post-Hartree–Fock methods, and related response interfaces are not implemented currently.

  • Newton/SOSCF is not implemented for CIDER PySCF calculations for all packaged families: the CIDER NumInt leaves the fxc and cache_xc_kernel entry points that second-order SCF requires unimplemented. Use the DIIS methods in Handling SCF Convergence Issues.

  • Nonlocal features add memory and communication overhead. GPAW exposes augmented-grid parallelization through parallel={"augment_grids": True}.

  • The documented feature interfaces cover semilocal, NLDF, and SDMX models. Other feature classes in the source tree are experimental.

Concrete restart controls for open-shell, near-degenerate, metallic, and magnetic calculations are listed in Handling SCF Convergence Issues.