#!/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.
#
# Author: Qiming Sun <osirpt.sun@gmail.com>
#
'''
Non-relativistic unrestricted Kohn-Sham for periodic systems at a single k-point
See Also:
pyscf.pbc.dft.krks.py : Non-relativistic Restricted Kohn-Sham for periodic
systems with k-point sampling
'''
import numpy
import pyscf.dft
from pyscf import lib
from pyscf.pbc.scf import uhf as pbcuhf
from pyscf.lib import logger
from pyscf.dft import uks as mol_uks
from pyscf.pbc.dft import gen_grid
from pyscf.pbc.dft import rks
from pyscf.pbc.dft import multigrid
from pyscf import __config__
get_rho = rks.get_rho
[docs]
def get_veff(ks, cell=None, dm=None, dm_last=0, vhf_last=0, hermi=1,
kpt=None, kpts_band=None):
'''Coulomb + XC functional for UKS. See pyscf/pbc/dft/uks.py
:func:`get_veff` fore more details.
'''
if cell is None: cell = ks.cell
if dm is None: dm = ks.make_rdm1()
if kpt is None: kpt = ks.kpt
t0 = (logger.process_clock(), logger.perf_counter())
ni = ks._numint
hybrid = ni.libxc.is_hybrid_xc(ks.xc)
if not hybrid and isinstance(ks.with_df, multigrid.MultiGridFFTDF):
if ks.do_nlc():
raise NotImplementedError(f'MultiGrid for NLC functional {ks.xc} + {ks.nlc}')
n, exc, vxc = multigrid.nr_uks(ks.with_df, ks.xc, dm, hermi,
kpt.reshape(1,3), kpts_band,
with_j=True, return_j=False)
logger.info(ks, 'nelec by numeric integration = %s', n)
t0 = logger.timer(ks, 'vxc', *t0)
return vxc
if not isinstance(dm, numpy.ndarray):
dm = numpy.asarray(dm)
if dm.ndim == 2: # RHF DM
dm = numpy.asarray((dm*.5,dm*.5))
# ndim = 3 : dm.shape = ([alpha,beta], nao, nao)
ground_state = (dm.ndim == 3 and dm.shape[0] == 2 and kpts_band is None)
ks.initialize_grids(cell, dm, kpt, ground_state)
if hermi == 2: # because rho = 0
n, exc, vxc = (0,0), 0, 0
else:
max_memory = ks.max_memory - lib.current_memory()[0]
n, exc, vxc = ni.nr_uks(cell, ks.grids, ks.xc, dm, 0, hermi,
kpt, kpts_band, max_memory=max_memory)
if ks.do_nlc():
if ni.libxc.is_nlc(ks.xc):
xc = ks.xc
else:
assert ni.libxc.is_nlc(ks.nlc)
xc = ks.nlc
n, enlc, vnlc = ni.nr_nlc_vxc(cell, ks.nlcgrids, xc, dm[0]+dm[1],
0, hermi, kpt, max_memory=max_memory)
exc += enlc
vxc += vnlc
logger.info(ks, 'nelec by numeric integration = %s', n)
t0 = logger.timer(ks, 'vxc', *t0)
if not hybrid:
vj = ks.get_j(cell, dm[0]+dm[1], hermi, kpt, kpts_band)
vxc += vj
else:
omega, alpha, hyb = ni.rsh_and_hybrid_coeff(ks.xc, spin=cell.spin)
vj, vk = ks.get_jk(cell, dm, hermi, kpt, kpts_band)
vj = vj[0] + vj[1]
vk *= hyb
if omega != 0:
vklr = ks.get_k(cell, dm, hermi, kpt, kpts_band, omega=omega)
vklr *= (alpha - hyb)
vk += vklr
vxc += vj - vk
if ground_state:
exc -=(numpy.einsum('ij,ji', dm[0], vk[0]) +
numpy.einsum('ij,ji', dm[1], vk[1])).real * .5
if ground_state:
ecoul = numpy.einsum('ij,ji', dm[0]+dm[1], vj).real * .5
else:
ecoul = None
vxc = lib.tag_array(vxc, ecoul=ecoul, exc=exc, vj=None, vk=None)
return vxc
[docs]
class UKS(rks.KohnShamDFT, pbcuhf.UHF):
'''UKS class adapted for PBCs.
This is a literal duplication of the molecular UKS class with some `mol`
variables replaced by `cell`.
'''
get_rho = get_rho
get_vsap = mol_uks.UKS.get_vsap
init_guess_by_vsap = mol_uks.UKS.init_guess_by_vsap
get_veff = get_veff
energy_elec = pyscf.dft.uks.energy_elec
def __init__(self, cell, kpt=numpy.zeros(3), xc='LDA,VWN',
exxdiv=getattr(__config__, 'pbc_scf_SCF_exxdiv', 'ewald')):
pbcuhf.UHF.__init__(self, cell, kpt, exxdiv=exxdiv)
rks.KohnShamDFT.__init__(self, xc)
[docs]
def dump_flags(self, verbose=None):
pbcuhf.UHF.dump_flags(self, verbose)
rks.KohnShamDFT.dump_flags(self, verbose)
return self
[docs]
def to_hf(self):
'''Convert to UHF object.'''
from pyscf.pbc import scf
return self._transfer_attrs_(scf.UHF(self.cell, self.kpt))
to_gpu = lib.to_gpu
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 = UKS(cell)
print(mf.kernel())
