PySCF Calculator Decoration

make_cider_calc() decorates a restricted or unrestricted PySCF Kohn–Sham object with a mapped CIDER functional. The mlfunc argument accepts a packaged name, trusted model path, or loaded MappedXC/ MappedXC2 object. The decorator selects its numerical integrator from the stored feature settings and supplies CIDER energy, potential, checkpoint, density-fitting, and supported gradient behavior.

Exchange models use xmix, xkernel, and ckernel to define their surrogate-hybrid composition. Full-XC models use their serialized energy composition. D4 metadata is reconciled after the SCF energy as described in Choosing a CIDER Functional.

The basic full-XC use case is:

from pyscf import gto
from pyscf.dft import RKS

from ciderpress.pyscf.dft import make_cider_calc

mol = gto.M(...)
ks = RKS(mol)
ks = make_cider_calc(ks, "CIDER26XCCHEM")
etot = ks.kernel()

See examples/pyscf/production_calc.py and Molecular Calculations with PySCF for a complete example.

ciderpress.pyscf.dft.make_cider_calc(ks, mlfunc, xmix=1.0, xc=None, xkernel=None, ckernel=None, mlfunc_format=None, nlc_coeff=None, nldf_init=None, sdmx_init=None, rhocut=None)

Decorate the PySCF DFT object ks with a CIDER functional mlfunc. If xc, xkernel, ckernel, and xmix are not specified, the equivalent of HF with CIDER in place of EXX is performed. The XC energy is:

E_xc = xmix * E_x^CIDER + (1-xmix) * xkernel + ckernel + xc

Mapped full-XC models already contain their complete baseline and require xmix=1.0, xc=None, xkernel=None, and ckernel=None (the defaults). Other compositions are rejected to prevent double counting.

NOTE: Only GGA-level XC functionals can be used with GGA-level (orbital-independent) CIDER functionals currently.

Parameters:

  • ks (pyscf.dft.KohnShamDFT) – DFT object

  • mlfunc (MappedXC, MappedXC2, str) – CIDER exchange functional or file name

  • xmix (float) – Fraction of CIDER exchange used.

  • xc (str or None) – If specified, this semi-local XC code is evaluated and added to the total XC energy.

  • xkernel (str or None) – Semi-local X code in libxc. Scaled by (1-xmix).

  • ckernel (str or None) – Semi-local C code in libxc.

  • mlfunc_format (str or None) – ‘joblib’ or ‘yaml’, specifies the format of mlfunc if it is a string corresponding to a file name. If unspecified, infer from file extension and raise error if file type cannot be determined.

  • nlc_coeff (tuple or None) – VV10 coefficients. If None, VV10 term is not evaluated.

  • nldf_init (PySCFNLDFInitializer)

  • sdmx_init (PySCFSDMXInitializer)

  • rhocut (float)

Returns:

A decorated Kohn-Sham object for performing a CIDER calculation.