Using Pylibnxc with PySCF

Using Pylibnxc in PySCF is as simple as changing two lines of code:

Starting from:

from pyscf import gto
from pyscf.dft import RKS

mol = gto.M(atom='H 0 0 0; H 0 0 0.7', basis='6-311G')
mf = RKS(mol)
mf.xc = 'PBE'
mf.kernel()

one can use pylibnxc:

from pyscf import gto
from pylibnxc.pyscf import RKS

mol = gto.M(atom='H 0 0 0; H 0 0 0.7', basis='6-311G')
mf = RKS(mol, nxc='GGA_PBE', nxc_kind='grid')
mf.kernel()

The second version would run a SCF calculation using our machine-learned version of PBE (see [Shipped functionals](#shipped-functionals).

For unrestricted Kohn-Sham calculations `pylibnxc.pyscf.UKS is available as well. The nxc keyword supports mixing of functionals similar to pyscf, e.g. `nxc ='0.25*HF + 0.75*GGA_X_PBE, GGA_C_PBE' would correspond to a neural network version of PBE0. Currently, mixing of libxc functionals with libnxc functionals is not supported.