#!/usr/bin/env python
# Copyright 2014-2019 The PySCF Developers. All Rights Reserved.
#
# 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.
#
# Authors: Qiming Sun <osirpt.sun@gmail.com>
#
'''
Restricted open-shell Kohn-Sham for periodic systems with k-point sampling
'''
import numpy as np
from pyscf import lib
from pyscf.pbc.scf import krohf
from pyscf.pbc.dft import rks
from pyscf.pbc.dft import kuks
from pyscf.pbc.dft.kuks import energy_elec
from pyscf import __config__
[docs]
@lib.with_doc(kuks.get_veff.__doc__)
def get_veff(ks, cell=None, dm=None, dm_last=0, vhf_last=0, hermi=1,
kpts=None, kpts_band=None):
if getattr(dm, 'mo_coeff', None) is not None:
mo_coeff = dm.mo_coeff
mo_occ_a = [(x > 0).astype(np.double) for x in dm.mo_occ]
mo_occ_b = [(x ==2).astype(np.double) for x in dm.mo_occ]
dm = lib.tag_array(dm, mo_coeff=(mo_coeff,mo_coeff),
mo_occ=(mo_occ_a,mo_occ_b))
return kuks.get_veff(ks, cell, dm, dm_last, vhf_last, hermi, kpts, kpts_band)
[docs]
class KROKS(rks.KohnShamDFT, krohf.KROHF):
'''RKS class adapted for PBCs with k-point sampling.
'''
get_veff = get_veff
energy_elec = energy_elec
get_rho = kuks.get_rho
def __init__(self, cell, kpts=np.zeros((1,3)), xc='LDA,VWN',
exxdiv=getattr(__config__, 'pbc_scf_SCF_exxdiv', 'ewald')):
krohf.KROHF.__init__(self, cell, kpts, exxdiv=exxdiv)
rks.KohnShamDFT.__init__(self, xc)
[docs]
def dump_flags(self, verbose=None):
krohf.KROHF.dump_flags(self, verbose)
rks.KohnShamDFT.dump_flags(self, verbose)
return self
[docs]
def to_hf(self):
'''Convert to KROHF object.'''
from pyscf.pbc import scf
return self._transfer_attrs_(scf.KROHF(self.cell, self.kpts))
if __name__ == '__main__':
from pyscf.pbc import gto
cell = gto.Cell()
cell.unit = 'A'
cell.atom = 'C 0., 0., 0.; C 0.8917, 0.8917, 0.8917'
cell.a = '''0. 1.7834 1.7834
1.7834 0. 1.7834
1.7834 1.7834 0. '''
cell.basis = 'gth-szv'
cell.pseudo = 'gth-pade'
cell.verbose = 7
cell.output = '/dev/null'
cell.build()
mf = KROKS(cell, cell.make_kpts([2,1,1]))
print(mf.kernel())