#!/usr/bin/env python

#

# This code was copied from the data generation program of Tencent Alchemy

# project (https://github.com/tencent-alchemy).

#

#

# Copyright 2019 Tencent America LLC. 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 <[email protected]>

#

import numpy

from pyscf import lib

from pyscf.lib import logger

from pyscf.grad import uhf as uhf_grad

from pyscf.df.grad import rhf as df_rhf_grad

class Gradients(uhf_grad.Gradients):

'''Unrestricted density-fitting Hartree-Fock gradients'''

_keys = {'with_df', 'auxbasis_response'}

def __init__(self, mf):

uhf_grad.Gradients.__init__(self, mf)

# Whether to include the response of DF auxiliary basis when computing

# nuclear gradients of J/K matrices

auxbasis_response = True

get_jk = df_rhf_grad.Gradients.get_jk

get_j = df_rhf_grad.Gradients.get_j

get_k = df_rhf_grad.Gradients.get_k

def get_veff(self, mol=None, dm=None):

vj, vk = self.get_jk(mol, dm)

vhf = vj[0]+vj[1] - vk

if self.auxbasis_response:

e1_aux = vj.aux.sum ((0,1))

e1_aux -= numpy.trace (vk.aux, axis1=0, axis2=1)

logger.debug1(self, 'sum(auxbasis response) %s', e1_aux.sum(axis=0))

vhf = lib.tag_array(vhf, aux=e1_aux)

return vhf

def extra_force(self, atom_id, envs):

if self.auxbasis_response:

return envs['vhf'].aux[atom_id]

else:

return 0

Grad = Gradients