#!/usr/bin/env python
# Copyright 2014-2021 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>
#
import ctypes
import warnings
import numpy
from pyscf import lib
from pyscf.lib import logger
from pyscf import ao2mo
from pyscf.fci import direct_spin1
from pyscf.fci import direct_spin1_symm
from pyscf.fci import selected_ci
from pyscf.fci import addons
libfci = direct_spin1.libfci
[docs]
def reorder4irrep(eri, norb, link_index, orbsym, offdiag=0):
if orbsym is None:
return eri, link_index, numpy.array(norb, dtype=numpy.int32)
orbsym = numpy.asarray(orbsym)
# map irrep IDs of Dooh or Coov to D2h, C2v
# see symm.basis.linearmole_symm_descent
orbsym = orbsym % 10
# irrep of (ij| pair
trilirrep = (orbsym[:,None] ^ orbsym)[numpy.tril_indices(norb, offdiag)]
# and the number of occurrences for each irrep
dimirrep = numpy.array(numpy.bincount(trilirrep), dtype=numpy.int32)
# we sort the irreps of (ij| pair, to group the pairs which have same irreps
# "order" is irrep-id-sorted index. The (ij| paired is ordered that the
# pair-id given by order[0] comes first in the sorted pair
# "rank" is a sorted "order". Given nth (ij| pair, it returns the place(rank)
# of the sorted pair
order = numpy.asarray(trilirrep.argsort(), dtype=numpy.int32)
rank = numpy.asarray(order.argsort(), dtype=numpy.int32)
eri = lib.take_2d(eri, order, order)
link_index_irrep = link_index.copy()
link_index_irrep[:,:,0] = rank[link_index[:,:,0]]
return numpy.asarray(eri, order='C'), link_index_irrep, dimirrep
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def contract_2e(eri, civec_strs, norb, nelec, link_index=None, orbsym=None):
ci_coeff, nelec, ci_strs = selected_ci._unpack(civec_strs, nelec)
if link_index is None:
link_index = selected_ci._all_linkstr_index(ci_strs, norb, nelec)
cd_indexa, dd_indexa, cd_indexb, dd_indexb = link_index
na, nlinka = cd_indexa.shape[:2]
nb, nlinkb = cd_indexb.shape[:2]
eri = ao2mo.restore(1, eri, norb)
eri1 = eri.transpose(0,2,1,3) - eri.transpose(0,2,3,1)
idx,idy = numpy.tril_indices(norb, -1)
idx = idx * norb + idy
eri1 = lib.take_2d(eri1.reshape(norb**2,-1), idx, idx) * 2
eri1, dd_indexa, dimirrep = reorder4irrep(eri1, norb, dd_indexa, orbsym, -1)
dd_indexb = reorder4irrep(eri1, norb, dd_indexb, orbsym, -1)[1]
fcivec = ci_coeff.reshape(na,nb)
# (bb|bb)
if nelec[1] > 1:
mb, mlinkb = dd_indexb.shape[:2]
fcivecT = lib.transpose(fcivec)
ci1T = numpy.zeros((nb,na))
libfci.SCIcontract_2e_aaaa_symm(eri1.ctypes.data_as(ctypes.c_void_p),
fcivecT.ctypes.data_as(ctypes.c_void_p),
ci1T.ctypes.data_as(ctypes.c_void_p),
ctypes.c_int(norb),
ctypes.c_int(nb), ctypes.c_int(na),
ctypes.c_int(mb), ctypes.c_int(mlinkb),
dd_indexb.ctypes.data_as(ctypes.c_void_p),
dimirrep.ctypes.data_as(ctypes.c_void_p),
ctypes.c_int(len(dimirrep)))
ci1 = lib.transpose(ci1T, out=fcivecT)
else:
ci1 = numpy.zeros_like(fcivec)
# (aa|aa)
if nelec[0] > 1:
ma, mlinka = dd_indexa.shape[:2]
libfci.SCIcontract_2e_aaaa_symm(eri1.ctypes.data_as(ctypes.c_void_p),
fcivec.ctypes.data_as(ctypes.c_void_p),
ci1.ctypes.data_as(ctypes.c_void_p),
ctypes.c_int(norb),
ctypes.c_int(na), ctypes.c_int(nb),
ctypes.c_int(ma), ctypes.c_int(mlinka),
dd_indexa.ctypes.data_as(ctypes.c_void_p),
dimirrep.ctypes.data_as(ctypes.c_void_p),
ctypes.c_int(len(dimirrep)))
h_ps = numpy.einsum('pqqs->ps', eri)
eri1 = eri * 2
for k in range(norb):
eri1[:,:,k,k] += h_ps/nelec[0]
eri1[k,k,:,:] += h_ps/nelec[1]
eri1 = ao2mo.restore(4, eri1, norb)
eri1, cd_indexa, dimirrep = reorder4irrep(eri1, norb, cd_indexa, orbsym)
cd_indexb = reorder4irrep(eri1, norb, cd_indexb, orbsym)[1]
# (bb|aa)
libfci.SCIcontract_2e_bbaa_symm(eri1.ctypes.data_as(ctypes.c_void_p),
fcivec.ctypes.data_as(ctypes.c_void_p),
ci1.ctypes.data_as(ctypes.c_void_p),
ctypes.c_int(norb),
ctypes.c_int(na), ctypes.c_int(nb),
ctypes.c_int(nlinka), ctypes.c_int(nlinkb),
cd_indexa.ctypes.data_as(ctypes.c_void_p),
cd_indexb.ctypes.data_as(ctypes.c_void_p),
dimirrep.ctypes.data_as(ctypes.c_void_p),
ctypes.c_int(len(dimirrep)))
return selected_ci._as_SCIvector(ci1.reshape(ci_coeff.shape), ci_strs)
[docs]
def kernel(h1e, eri, norb, nelec, ci0=None, level_shift=1e-3, tol=1e-10,
lindep=1e-14, max_cycle=50, max_space=12, nroots=1,
davidson_only=False, pspace_size=400, orbsym=None, wfnsym=None,
select_cutoff=1e-3, ci_coeff_cutoff=1e-3, ecore=0, **kwargs):
return direct_spin1._kfactory(SelectedCI, h1e, eri, norb, nelec, ci0,
level_shift, tol, lindep, max_cycle,
max_space, nroots, davidson_only,
pspace_size, select_cutoff=select_cutoff,
ci_coeff_cutoff=ci_coeff_cutoff, ecore=ecore,
**kwargs)
make_rdm1s = selected_ci.make_rdm1s
make_rdm2s = selected_ci.make_rdm2s
make_rdm1 = selected_ci.make_rdm1
make_rdm2 = selected_ci.make_rdm2
trans_rdm1s = selected_ci.trans_rdm1s
trans_rdm1 = selected_ci.trans_rdm1
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class SelectedCI(selected_ci.SelectedCI):
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def contract_2e(self, eri, civec_strs, norb, nelec, link_index=None,
orbsym=None, **kwargs):
if orbsym is None:
orbsym = self.orbsym
if getattr(civec_strs, '_strs', None) is not None:
self._strs = civec_strs._strs
else:
assert (civec_strs.size == len(self._strs[0])*len(self._strs[1]))
civec_strs = selected_ci._as_SCIvector(civec_strs, self._strs)
return contract_2e(eri, civec_strs, norb, nelec, link_index, orbsym)
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def get_init_guess(self, ci_strs, norb, nelec, nroots, hdiag):
'''Initial guess is the single Slater determinant
'''
wfnsym = direct_spin1_symm._id_wfnsym(self, norb, nelec, self.orbsym,
self.wfnsym)
airreps = direct_spin1_symm._gen_strs_irrep(ci_strs[0], self.orbsym)
birreps = direct_spin1_symm._gen_strs_irrep(ci_strs[1], self.orbsym)
ci0 = direct_spin1_symm._get_init_guess(
airreps, birreps, nroots, hdiag, nelec, self.orbsym, wfnsym)
return [selected_ci._as_SCIvector(x, ci_strs) for x in ci0]
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def guess_wfnsym(self, norb, nelec, fcivec=None, orbsym=None, wfnsym=None,
**kwargs):
if orbsym is None:
orbsym = self.orbsym
if fcivec is None:
wfnsym = direct_spin1_symm._id_wfnsym(self, norb, nelec, orbsym, wfnsym)
elif wfnsym is None:
strsa, strsb = getattr(fcivec, '_strs', self._strs)
if isinstance(fcivec, numpy.ndarray) and fcivec.ndim <= 2:
wfnsym = addons._guess_wfnsym(fcivec, strsa, strsb, orbsym)
else:
wfnsym = [addons._guess_wfnsym(c, strsa, strsb, orbsym)
for c in fcivec]
if any(wfnsym[0] != x for x in wfnsym):
warnings.warn('Different wfnsym %s found in different CI vecotrs' % wfnsym)
wfnsym = wfnsym[0]
else:
strsa, strsb = getattr(fcivec, '_strs', self._strs)
na, nb = strsa.size, strsb.size
orbsym_in_d2h = numpy.asarray(orbsym) % 10 # convert to D2h irreps
airreps = numpy.zeros(na, dtype=numpy.int32)
birreps = numpy.zeros(nb, dtype=numpy.int32)
for i, ir in enumerate(orbsym_in_d2h):
airreps[numpy.bitwise_and(strsa, 1 << i) > 0] ^= ir
birreps[numpy.bitwise_and(strsb, 1 << i) > 0] ^= ir
wfnsym = direct_spin1_symm._id_wfnsym(self, norb, nelec, orbsym, wfnsym)
mask = (airreps.reshape(-1,1) ^ birreps) == wfnsym
if isinstance(fcivec, numpy.ndarray) and fcivec.ndim <= 2:
fcivec = [fcivec]
if all(abs(c.reshape(na, nb)[mask]).max() < 1e-5 for c in fcivec):
raise RuntimeError('Input wfnsym is not consistent with fcivec coefficients')
verbose = kwargs.get('verbose', None)
log = logger.new_logger(self, verbose)
log.debug('Guessing CI wfn symmetry = %s', wfnsym)
return wfnsym
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def kernel(self, h1e, eri, norb, nelec, ci0=None,
tol=None, lindep=None, max_cycle=None, max_space=None,
nroots=None, davidson_only=None, pspace_size=None,
orbsym=None, wfnsym=None, ecore=0, **kwargs):
if nroots is None: nroots = self.nroots
if orbsym is None: orbsym = self.orbsym
if wfnsym is None: wfnsym = self.wfnsym
if self.verbose >= logger.WARN:
self.check_sanity()
if getattr(self.mol, 'groupname', None) in ('Dooh', 'Coov'):
raise NotImplementedError
with lib.temporary_env(self, orbsym=orbsym, wfnsym=wfnsym):
e, c = selected_ci.kernel_float_space(self, h1e, eri, norb, nelec, ci0,
tol, lindep, max_cycle, max_space,
nroots, davidson_only, ecore=ecore,
**kwargs)
if wfnsym is not None:
wfnsym0 = self.guess_wfnsym(norb, nelec, ci0, orbsym, wfnsym, **kwargs)
strsa, strsb = c._strs
if nroots > 1:
for i, ci in enumerate(c):
ci = addons._symmetrize_wfn(ci, strsa, strsb, self.orbsym, wfnsym0)
c[i] = selected_ci._as_SCIvector(ci, c._strs)
else:
ci = addons._symmetrize_wfn(c, strsa, strsb, self.orbsym, wfnsym0)
c = selected_ci._as_SCIvector(ci, c._strs)
self.eci, self.ci = e, c
return e, c
SCI = SelectedCI
if __name__ == '__main__':
from functools import reduce
from pyscf import gto
from pyscf import scf
from pyscf import symm
from pyscf.fci import cistring
norb, nelec = 7, (4,4)
strs = cistring.gen_strings4orblist(range(norb), nelec[0])
numpy.random.seed(11)
mask = numpy.random.random(len(strs)) > .3
strsa = strs[mask]
mask = numpy.random.random(len(strs)) > .2
strsb = strs[mask]
ci_strs = (strsa, strsb)
civec_strs = selected_ci._as_SCIvector(numpy.random.random((len(strsa),len(strsb))), ci_strs)
orbsym = (numpy.random.random(norb) * 4).astype(int)
nn = norb*(norb+1)//2
eri = (numpy.random.random(nn*(nn+1)//2)-.2)**3
ci0 = selected_ci.to_fci(civec_strs, norb, nelec)
ci0 = addons.symmetrize_wfn(ci0, norb, nelec, orbsym)
civec_strs = selected_ci.from_fci(ci0, civec_strs._strs, norb, nelec)
e1 = numpy.dot(civec_strs.ravel(), contract_2e(eri, civec_strs, norb, nelec, orbsym=orbsym).ravel())
e2 = numpy.dot(ci0.ravel(), direct_spin1_symm.contract_2e(eri, ci0, norb, nelec, orbsym=orbsym).ravel())
print(e1-e2)
mol = gto.Mole()
mol.verbose = 0
mol.output = None
mol.atom = [
['O', ( 0., 0. , 0. )],
['H', ( 0., -0.757, 0.587)],
['H', ( 0., 0.757 , 0.587)],]
mol.basis = 'sto-3g'
mol.symmetry = 1
mol.build()
m = scf.RHF(mol).run()
norb = m.mo_coeff.shape[1]
nelec = mol.nelectron - 2
h1e = reduce(numpy.dot, (m.mo_coeff.T, scf.hf.get_hcore(mol), m.mo_coeff))
eri = ao2mo.incore.full(m._eri, m.mo_coeff)
orbsym = symm.label_orb_symm(mol, mol.irrep_id, mol.symm_orb, m.mo_coeff)
myci = SelectedCI().set(orbsym=orbsym)
e1, c1 = myci.kernel(h1e, eri, norb, nelec)
myci = direct_spin1_symm.FCISolver().set(orbsym=orbsym)
e2, c2 = myci.kernel(h1e, eri, norb, nelec)
print(e1 - e2)