#!/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>
# Timothy Berkelbach <tim.berkelbach@gmail.com>
#
'''
QCISD for real integrals
8-fold permutation symmetry has been used
(ij|kl) = (ji|kl) = (kl|ij) = ...
'''
import numpy
from pyscf import gto
from pyscf import lib
from pyscf.lib import logger
from pyscf.cc.ccsd import CCSDBase, as_scanner, _add_vvvv, _ChemistsERIs
from pyscf import __config__
BLKMIN = getattr(__config__, 'cc_ccsd_blkmin', 4)
MEMORYMIN = getattr(__config__, 'cc_ccsd_memorymin', 2000)
# t1: ia
# t2: ijab
[docs]
def kernel(mycc, eris=None, t1=None, t2=None, max_cycle=50, tol=1e-8,
tolnormt=1e-6, verbose=None):
log = logger.new_logger(mycc, verbose)
if eris is None:
eris = mycc.ao2mo(mycc.mo_coeff)
if t1 is None and t2 is None:
t1, t2 = mycc.get_init_guess(eris)
elif t2 is None:
t2 = mycc.get_init_guess(eris)[1]
cput1 = cput0 = (logger.process_clock(), logger.perf_counter())
eold = 0
eccsd = mycc.energy(t1, t2, eris)
log.info('Init E_corr(QCISD) = %.15g', eccsd)
if isinstance(mycc.diis, lib.diis.DIIS):
adiis = mycc.diis
elif mycc.diis:
adiis = lib.diis.DIIS(mycc, mycc.diis_file, incore=mycc.incore_complete)
adiis.space = mycc.diis_space
else:
adiis = None
conv = False
for istep in range(max_cycle):
t1new, t2new = mycc.update_amps(t1, t2, eris)
tmpvec = mycc.amplitudes_to_vector(t1new, t2new)
tmpvec -= mycc.amplitudes_to_vector(t1, t2)
normt = numpy.linalg.norm(tmpvec)
tmpvec = None
if mycc.iterative_damping < 1.0:
alpha = mycc.iterative_damping
t1new = (1-alpha) * t1 + alpha * t1new
t2new *= alpha
t2new += (1-alpha) * t2
t1, t2 = t1new, t2new
t1new = t2new = None
t1, t2 = mycc.run_diis(t1, t2, istep, normt, eccsd-eold, adiis)
eold, eccsd = eccsd, mycc.energy(t1, t2, eris)
log.info('cycle = %d E_corr(QCISD) = %.15g dE = %.9g norm(t1,t2) = %.6g',
istep+1, eccsd, eccsd - eold, normt)
cput1 = log.timer('QCISD iter', *cput1)
if abs(eccsd-eold) < tol and normt < tolnormt:
conv = True
break
log.timer('QCISD', *cput0)
return conv, eccsd, t1, t2
[docs]
def update_amps(mycc, t1, t2, eris):
assert (isinstance(eris, _ChemistsERIs))
time0 = logger.process_clock(), logger.perf_counter()
log = logger.Logger(mycc.stdout, mycc.verbose)
nocc, nvir = t1.shape
fock = eris.fock
mo_e_o = eris.mo_energy[:nocc]
mo_e_v = eris.mo_energy[nocc:] + mycc.level_shift
t1new = numpy.zeros_like(t1)
t2new = _add_vvvv(mycc, 0*t1, t2, eris, t2sym='jiba')
t2new *= .5 # *.5 because t2+t2.transpose(1,0,3,2) in the end
time1 = log.timer_debug1('vvvv', *time0)
#** make_inter_F
fov = fock[:nocc,nocc:].copy()
t1new += fov
foo = fock[:nocc,:nocc] - numpy.diag(mo_e_o)
fvv = fock[nocc:,nocc:] - numpy.diag(mo_e_v)
if mycc.incore_complete:
fswap = None
else:
fswap = lib.H5TmpFile()
fwVOov, fwVooV = _add_ovvv_(mycc, t1, t2, eris, fvv, t1new, t2new, fswap)
time1 = log.timer_debug1('ovvv', *time1)
woooo = numpy.asarray(eris.oooo).transpose(0,2,1,3).copy()
unit = nocc**2*nvir*7 + nocc**3 + nocc*nvir**2
mem_now = lib.current_memory()[0]
max_memory = max(0, mycc.max_memory - mem_now)
blksize = min(nvir, max(BLKMIN, int((max_memory*.9e6/8-nocc**4)/unit)))
log.debug1('max_memory %d MB, nocc,nvir = %d,%d blksize = %d',
max_memory, nocc, nvir, blksize)
for p0, p1 in lib.prange(0, nvir, blksize):
wVOov = fwVOov[p0:p1]
wVooV = fwVooV[p0:p1]
eris_ovoo = eris.ovoo[:,p0:p1]
eris_oovv = numpy.empty((nocc,nocc,p1-p0,nvir))
def load_oovv(p0, p1):
eris_oovv[:] = eris.oovv[:,:,p0:p1]
with lib.call_in_background(load_oovv, sync=not mycc.async_io) as prefetch_oovv:
#:eris_oovv = eris.oovv[:,:,p0:p1]
prefetch_oovv(p0, p1)
wVOov -= lib.einsum('jbik,ka->bjia', eris_ovoo, t1)
t2new[:,:,p0:p1] += wVOov.transpose(1,2,0,3)
eris_ovoo = None
load_oovv = prefetch_oovv = None
wVOov *= 0 # QCI
eris_ovvo = numpy.empty((nocc,p1-p0,nvir,nocc))
def load_ovvo(p0, p1):
eris_ovvo[:] = eris.ovvo[:,p0:p1]
with lib.call_in_background(load_ovvo, sync=not mycc.async_io) as prefetch_ovvo:
#:eris_ovvo = eris.ovvo[:,p0:p1]
prefetch_ovvo(p0, p1)
t1new[:,p0:p1] -= numpy.einsum('jb,jiab->ia', t1, eris_oovv)
wVooV -= eris_oovv.transpose(2,0,1,3)
wVOov += wVooV*.5 #: bjia + bija*.5
load_ovvo = prefetch_ovvo = None
t2new[:,:,p0:p1] += (eris_ovvo*0.5).transpose(0,3,1,2)
eris_voov = eris_ovvo.conj().transpose(1,0,3,2)
t1new[:,p0:p1] += 2*numpy.einsum('jb,aijb->ia', t1, eris_voov)
eris_ovvo = None
eris_oovv = tmp = None
fov[:,p0:p1] += numpy.einsum('kc,aikc->ia', t1, eris_voov) * 2
fov[:,p0:p1] -= numpy.einsum('kc,akic->ia', t1, eris_voov)
tau = t2[:,:,p0:p1]
theta = tau.transpose(1,0,2,3) * 2
theta -= tau
fvv -= lib.einsum('cjia,cjib->ab', theta.transpose(2,1,0,3), eris_voov)
foo += lib.einsum('aikb,kjab->ij', eris_voov, theta)
theta = None
woooo += lib.einsum('ijab,aklb->ijkl', tau, eris_voov)
tau = None
def update_wVooV(q0, q1, tau):
wVooV[:] += lib.einsum('bkic,jkca->bija', eris_voov[:,:,:,q0:q1], tau)
with lib.call_in_background(update_wVooV, sync=not mycc.async_io) as update_wVooV:
for q0, q1 in lib.prange(0, nvir, blksize):
tau = t2[:,:,q0:q1] * .5
#:wVooV += lib.einsum('bkic,jkca->bija', eris_voov[:,:,:,q0:q1], tau)
update_wVooV(q0, q1, tau)
tau = update_wVooV = None
def update_t2(q0, q1, tmp):
t2new[:,:,q0:q1] += tmp.transpose(2,0,1,3)
tmp *= .5
t2new[:,:,q0:q1] += tmp.transpose(0,2,1,3)
with lib.call_in_background(update_t2, sync=not mycc.async_io) as update_t2:
for q0, q1 in lib.prange(0, nvir, blksize):
tmp = lib.einsum('jkca,ckib->jaib', t2[:,:,p0:p1,q0:q1], wVooV)
#:t2new[:,:,q0:q1] += tmp.transpose(2,0,1,3)
#:tmp *= .5
#:t2new[:,:,q0:q1] += tmp.transpose(0,2,1,3)
update_t2(q0, q1, tmp)
tmp = None
wVOov += eris_voov
eris_VOov = -.5 * eris_voov.transpose(0,2,1,3)
eris_VOov += eris_voov
eris_voov = None
def update_wVOov(q0, q1, tau):
wVOov[:,:,:,q0:q1] += .5 * lib.einsum('aikc,kcjb->aijb', eris_VOov, tau)
with lib.call_in_background(update_wVOov, sync=not mycc.async_io) as update_wVOov:
for q0, q1 in lib.prange(0, nvir, blksize):
tau = t2[:,:,q0:q1].transpose(1,3,0,2) * 2
tau -= t2[:,:,q0:q1].transpose(0,3,1,2)
#:wVOov[:,:,:,q0:q1] += .5 * lib.einsum('aikc,kcjb->aijb', eris_VOov, tau)
update_wVOov(q0, q1, tau)
tau = None
def update_t2(q0, q1, theta):
t2new[:,:,q0:q1] += lib.einsum('kica,ckjb->ijab', theta, wVOov)
with lib.call_in_background(update_t2, sync=not mycc.async_io) as update_t2:
for q0, q1 in lib.prange(0, nvir, blksize):
theta = t2[:,:,p0:p1,q0:q1] * 2
theta -= t2[:,:,p0:p1,q0:q1].transpose(1,0,2,3)
#:t2new[:,:,q0:q1] += lib.einsum('kica,ckjb->ijab', theta, wVOov)
update_t2(q0, q1, theta)
theta = None
eris_VOov = wVOov = wVooV = update_wVOov = None
time1 = log.timer_debug1('voov [%d:%d]'%(p0, p1), *time1)
fwVOov = fwVooV = fswap = None
for p0, p1 in lib.prange(0, nvir, blksize):
theta = t2[:,:,p0:p1].transpose(1,0,2,3) * 2 - t2[:,:,p0:p1]
t1new += numpy.einsum('jb,ijba->ia', fov[:,p0:p1], theta)
t1new -= lib.einsum('jbki,kjba->ia', eris.ovoo[:,p0:p1], theta)
tau = t2[:,:,p0:p1]
t2new[:,:,p0:p1] += .5 * lib.einsum('ijkl,klab->ijab', woooo, tau)
theta = tau = None
t2new += lib.einsum('ijac,bc->ijab', t2, fvv)
t2new -= lib.einsum('ki,kjab->ijab', foo, t2)
eia = mo_e_o[:,None] - mo_e_v
t1new += numpy.einsum('ib,ab->ia', t1, fvv)
t1new -= numpy.einsum('ja,ji->ia', t1, foo)
t1new /= eia
#: t2new = t2new + t2new.transpose(1,0,3,2)
for i in range(nocc):
if i > 0:
t2new[i,:i] += t2new[:i,i].transpose(0,2,1)
t2new[i,:i] /= lib.direct_sum('a,jb->jab', eia[i], eia[:i])
t2new[:i,i] = t2new[i,:i].transpose(0,2,1)
t2new[i,i] = t2new[i,i] + t2new[i,i].T
t2new[i,i] /= lib.direct_sum('a,b->ab', eia[i], eia[i])
time0 = log.timer_debug1('update t1 t2', *time0)
return t1new, t2new
def _add_ovvv_(mycc, t1, t2, eris, fvv, t1new, t2new, fswap):
time1 = logger.process_clock(), logger.perf_counter()
log = logger.Logger(mycc.stdout, mycc.verbose)
nocc, nvir = t1.shape
nvir_pair = nvir * (nvir+1) // 2
if fswap is None:
wVOov = numpy.zeros((nvir,nocc,nocc,nvir))
else:
wVOov = fswap.create_dataset('wVOov', (nvir,nocc,nocc,nvir), 'f8')
wooVV = numpy.zeros((nocc,nocc*nvir_pair))
max_memory = mycc.max_memory - lib.current_memory()[0]
unit = nocc*nvir**2*3 + nocc**2*nvir + 2
blksize = min(nvir, max(BLKMIN, int((max_memory*.95e6/8-wooVV.size)/unit)))
if not mycc.direct:
unit = nocc*nvir**2*3 + nocc**2*nvir + 2 + nocc*nvir**2 + nocc*nvir
blksize = min(nvir, max(BLKMIN, int((max_memory*.95e6/8-wooVV.size-nocc**2*nvir)/unit)))
log.debug1('max_memory %d MB, nocc,nvir = %d,%d blksize = %d',
max_memory, nocc, nvir, blksize)
def load_ovvv(buf, p0):
if p0 < nvir:
p1 = min(nvir, p0+blksize)
buf[:p1-p0] = eris.ovvv[:,p0:p1].transpose(1,0,2)
with lib.call_in_background(load_ovvv, sync=not mycc.async_io) as prefetch:
buf = numpy.empty((blksize,nocc,nvir_pair))
buf_prefetch = numpy.empty((blksize,nocc,nvir_pair))
load_ovvv(buf_prefetch, 0)
for p0, p1 in lib.prange(0, nvir, blksize):
buf, buf_prefetch = buf_prefetch, buf
prefetch(buf_prefetch, p1)
eris_vovv = buf[:p1-p0]
eris_vovv = lib.unpack_tril(eris_vovv.reshape((p1-p0)*nocc,nvir_pair))
eris_vovv = eris_vovv.reshape(p1-p0,nocc,nvir,nvir)
wVOov[p0:p1] = lib.einsum('biac,jc->bija', eris_vovv, t1)
theta = t2[:,:,p0:p1].transpose(1,2,0,3) * 2
theta -= t2[:,:,p0:p1].transpose(0,2,1,3)
t1new += lib.einsum('icjb,cjba->ia', theta, eris_vovv)
theta = None
time1 = log.timer_debug1('vovv [%d:%d]'%(p0, p1), *time1)
if fswap is None:
wooVV = lib.unpack_tril(wooVV.reshape(nocc**2,nvir_pair))
return wVOov, wooVV.reshape(nocc,nocc,nvir,nvir).transpose(2,1,0,3)
else:
fswap.create_dataset('wVooV', (nvir,nocc,nocc,nvir), 'f8')
wooVV = wooVV.reshape(nocc,nocc,nvir_pair)
tril2sq = lib.square_mat_in_trilu_indices(nvir)
for p0, p1 in lib.prange(0, nvir, blksize):
fswap['wVooV'][p0:p1] = wooVV[:,:,tril2sq[p0:p1]].transpose(2,1,0,3)
return fswap['wVOov'], fswap['wVooV']
[docs]
def energy(mycc, t1=None, t2=None, eris=None):
'''QCISD correlation energy'''
if t1 is None: t1 = mycc.t1
if t2 is None: t2 = mycc.t2
if eris is None: eris = mycc.ao2mo()
nocc, nvir = t1.shape
fock = eris.fock
e = numpy.einsum('ia,ia', fock[:nocc,nocc:], t1) * 2
max_memory = mycc.max_memory - lib.current_memory()[0]
blksize = int(min(nvir, max(BLKMIN, max_memory*.3e6/8/(nocc**2*nvir+1))))
for p0, p1 in lib.prange(0, nvir, blksize):
eris_ovvo = eris.ovvo[:,p0:p1]
tau = t2[:,:,p0:p1]
e += 2 * numpy.einsum('ijab,iabj', tau, eris_ovvo)
e -= numpy.einsum('jiab,iabj', tau, eris_ovvo)
if abs(e.imag) > 1e-4:
logger.warn(mycc, 'Non-zero imaginary part found in QCISD energy %s', e)
return e.real
[docs]
class QCISD(CCSDBase):
'''restricted QCISD
'''
[docs]
def dump_flags(self, verbose=None):
log = logger.new_logger(self, verbose)
log.info('')
log.info('******** %s ********', self.__class__)
log.info('QCISD nocc = %s, nmo = %s', self.nocc, self.nmo)
if self.frozen is not None:
log.info('frozen orbitals %s', self.frozen)
log.info('max_cycle = %d', self.max_cycle)
log.info('direct = %d', self.direct)
log.info('conv_tol = %g', self.conv_tol)
log.info('conv_tol_normt = %s', self.conv_tol_normt)
log.info('diis_space = %d', self.diis_space)
#log.info('diis_file = %s', self.diis_file)
log.info('diis_start_cycle = %d', self.diis_start_cycle)
log.info('diis_start_energy_diff = %g', self.diis_start_energy_diff)
log.info('max_memory %d MB (current use %d MB)',
self.max_memory, lib.current_memory()[0])
return self
energy = energy
_add_vvvv = _add_vvvv
update_amps = update_amps
kernel = CCSDBase.ccsd
ccsd = lib.invalid_method('ccsd')
as_scanner = as_scanner
[docs]
def qcisd_t(self, t1=None, t2=None, eris=None):
from pyscf.cc import qcisd_t
if t1 is None: t1 = self.t1
if t2 is None: t2 = self.t2
if eris is None: eris = self.ao2mo(self.mo_coeff)
return qcisd_t.kernel(self, eris, t1, t2, self.verbose)
RQCISD = QCISD
