pyscf/pyscf/df/__init__.py at master · pyscf/pyscf

Repository navigation

#!/usr/bin/env python

# Licensed under the Apache License, Version 2.0 (the "License");

# you may not use this file except in compliance with the License.

# You may obtain a copy of the License at

# http://www.apache.org/licenses/LICENSE-2.0

# Unless required by applicable law or agreed to in writing, software

# distributed under the License is distributed on an "AS IS" BASIS,

# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

# See the License for the specific language governing permissions and

# limitations under the License.

# Author: Qiming Sun <osirpt.sun@gmail.com>

'''

Density fitting

===============

This module provides the fundamental functions to handle the 3-index tensors

(including the 3-center 2-electron AO and MO integrals, the Cholesky

decomposed integrals) required by the density fitting method or the RI

(resolution of identity) approximation.

Simple usage::

>>> from pyscf import gto, dft

>>> mol = gto.M(atom='N 0 0 0; N 0 0 1', basis='ccpvdz')

>>> mf = dft.RKS(mol).density_fit().run()

'''

from . import incore

from . import outcore

from . import addons

from .addons import (load, aug_etb, autoaux, autoabs,

DEFAULT_AUXBASIS, make_auxbasis, make_auxmol)

from .df import DF, GDF, DF4C, GDF4C

from . import r_incore

def density_fit(obj, *args, **kwargs):

'''Given SCF/MCSCF or post-HF object, use density fitting technique to

approximate the 2e integrals.'''

return obj.density_fit(*args, **kwargs)