#!/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: Oliver Backhouse <olbackhouse@gmail.com>
#
"""
GF-CCSD solver via moment constraints.
See reference: Backhouse, Booth, arXiv:2206.13198 (2022).
"""
from collections import defaultdict
import numpy as np
import scipy.linalg
from pyscf import lib, cc, ao2mo
from pyscf.lib import logger
from pyscf.agf2 import mpi_helper
[docs]
def kernel(
gfccsd,
hole_moments=None,
part_moments=None,
t1=None,
t2=None,
l1=None,
l2=None,
eris=None,
imds=None,
verbose=None,
):
if gfccsd.verbose >= logger.WARN:
gfccsd.check_sanity()
gfccsd.dump_flags()
log = logger.new_logger(gfccsd, verbose)
if (l1 is None and gfccsd._cc.l1 is None) or (l2 is None and gfccsd._cc.l2 is None):
raise ValueError(
"Lambda amplitudes must be set for %s. This "
"can be done by calling solve_lambda on the "
"CC method or by setting l1, l2 attributes. "
% gfccsd.__class__.__name__
)
if (hole_moments is None or part_moments is None) and imds is None:
ip = hole_moments is None
ea = part_moments is None
imds = gfccsd.make_imds(eris=eris, ip=ip, ea=ea)
if hole_moments is None:
log.info("Building hole moments:")
hole_moments = gfccsd.build_hole_moments(t1=t1, t2=t2, l1=l1, l2=l2, imds=imds)
else:
log.info("Hole moments passed by argument.")
if part_moments is None:
log.info("Building particle moments:")
part_moments = gfccsd.build_part_moments(t1=t1, t2=t2, l1=l1, l2=l2, imds=imds)
else:
log.info("Particle moments passed by argument.")
if gfccsd.hermi_moments:
hole_moments = 0.5 * (hole_moments + hole_moments.swapaxes(1, 2).conj())
part_moments = 0.5 * (part_moments + part_moments.swapaxes(1, 2).conj())
if gfccsd.hermi_solver:
solver = block_lanczos_symm
eig = eigh_block_tridiagonal
else:
solver = block_lanczos_nosymm
eig = eig_block_tridiagonal
log.info("Solving for the hole moments.")
blocks = solver(gfccsd, hole_moments)
orth = mat_sqrt(hole_moments[0], hermi=gfccsd.hermi_solver)
eh, vh = eig(gfccsd, *blocks, orth=orth)
log.info("Solving for the particle moment.")
blocks = solver(gfccsd, part_moments)
orth = mat_sqrt(part_moments[0], hermi=gfccsd.hermi_solver)
ep, vp = eig(gfccsd, *blocks, orth=orth)
# Check the moments
if gfccsd.niter[0] is not None:
for n in range(2*gfccsd.niter[0]+2):
a = lib.einsum("xk,yk,k->xy", vh[0], vh[1].conj(), eh**n)
a /= np.max(np.abs(a))
b = hole_moments[n] / np.max(np.abs(hole_moments[n]))
err = np.max(np.abs(a - b))
(logger.debug1 if err < 1e-8 else logger.warn)(
gfccsd, "Error in hole moment %d: %10.6g", n, err)
if gfccsd.niter[0] is not None:
for n in range(2*gfccsd.niter[1]+2):
a = lib.einsum("xk,yk,k->xy", vp[0], vp[1].conj(), ep**n)
a /= np.max(np.abs(a))
b = part_moments[n] / np.max(np.abs(part_moments[n]))
err = np.max(np.abs(a - b))
(logger.debug1 if err < 1e-8 else logger.warn)(
gfccsd, "Error in particle moment %d: %10.6g", n, err)
mask = np.argsort(eh.real)
eh, vh = eh[mask], (vh[0][:, mask], vh[1][:, mask])
mask = np.argsort(ep.real)
ep, vp = ep[mask], (vp[0][:, mask], vp[1][:, mask])
return eh, vh, ep, vp
[docs]
def mat_sqrt(m, hermi=False):
"""Return the square root of a matrix.
"""
if hermi:
w, v = np.linalg.eigh(m)
mask = w >= 0
w, v = w[mask], v[:, mask]
out = np.dot(v * w[None]**0.5, v.T.conj())
else:
w, v = np.linalg.eig(m)
out = np.dot(v * w[None]**(0.5+0j), np.linalg.inv(v))
return out
[docs]
def mat_isqrt(m, tol=1e-16, hermi=False):
"""Return the inverse square root of a matrix.
"""
if hermi:
w, v = np.linalg.eigh(m)
mask = w > tol
w, v = w[mask], v[:, mask]
out = np.dot(v * w[None]**-0.5, v.T.conj())
else:
w, v = np.linalg.eig(m)
mask = np.abs(w) >= tol
vinv = np.linalg.inv(v)[mask]
w, v = w[mask], v[:, mask]
out = np.dot(v * w[None]**(-0.5+0j), vinv)
return out
[docs]
def build_block_tridiagonal(a, b, c=None):
"""Construct a block tridiagonal matrix from a list of on-diagonal
and off-diagonal blocks.
"""
z = np.zeros_like(a[0], dtype=a[0].dtype)
if c is None:
c = [x.T.conj() for x in b]
h = np.block([[
a[i] if i == j else
b[j] if j == i-1 else
c[i] if i == j-1 else z
for j in range(len(a))]
for i in range(len(a))]
)
return h
[docs]
def eig_block_tridiagonal(gfccsd, a, b, c, orth=None):
"""Diagonalise a non-Hermitian block-tridiagonal Hamiltonian and
transform its eigenvectors appropriately.
"""
h_tri = build_block_tridiagonal(a, b, c)
e, u = np.linalg.eig(h_tri)
if orth is not None:
vl = np.dot(orth, u[:gfccsd.nmo])
vr = np.dot(np.linalg.inv(u)[:, :gfccsd.nmo], orth).T.conj()
else:
vl = u[:gfccsd.nmo]
vr = np.linalg.inv(u)[:, :gfccsd.nmo].T.conj()
return e, (vl, vr)
[docs]
def eigh_block_tridiagonal(gfccsd, a, b, orth=None):
"""Diagonalise a Hermitian block-tridiagonal Hamiltonian and
transform its eigenvectors appropriately.
"""
h_tri = build_block_tridiagonal(a, b)
e, u = np.linalg.eigh(h_tri)
if orth is not None:
v = np.dot(orth, u[:gfccsd.nmo])
else:
v = u[:gfccsd.nmo]
return e, (v, v)
def _matrix_info(x, hermi=False):
norm = np.abs(np.einsum("pq,qp->", x, x))
eigvals = np.linalg.eigvals(x)
mineig = np.min(np.abs(eigvals))
maxeig = np.max(np.abs(eigvals))
return norm, mineig, maxeig
[docs]
def block_lanczos_symm(gfccsd, moments, verbose=None):
"""Hermitian block Lanczos solver, returns a set of poles that
best reproduce the inputted moments.
Args:
gfccsd : MomGFCCSD
GF-CCSD object
moments : ndarray (2*niter+2, n, n)
Array of moments with which the resulting poles should
be consistent with.
Kwargs:
verbose : int
Level of verbosity.
Returns:
a : ndarray (niter+1, n, n)
On-diagonal blocks of the block tridiagonal Hamiltonian.
b : ndarray (niter, n, n)
Off-diagonal blocks of the block tridiagonal Hamiltonian.
"""
log = logger.new_logger(gfccsd, verbose)
log.debug1("block_lanczos_symm: %d moments", len(moments))
nmo = gfccsd.nmo
niter = (len(moments) - 2) // 2
dtype = np.complex128
a = np.zeros((niter+1, nmo, nmo), dtype=dtype)
b = np.zeros((niter, nmo, nmo), dtype=dtype)
t = np.zeros((len(moments), nmo, nmo), dtype=dtype)
v = defaultdict(lambda: np.zeros((nmo, nmo), dtype=dtype))
v[0, 0] = np.eye(nmo).astype(dtype)
orth = mat_isqrt(moments[0], hermi=True)
for i in range(len(moments)):
t[i] = np.linalg.multi_dot((orth, moments[i], orth))
a[0] = t[1]
log.debug1("Raw moments:")
log.debug1(" %4s %12s %12s %12s", "N", "norm", "min(|eig|)", "max(|eig|)")
for i in range(len(moments)):
log.debug1(" %4d %12.6g %12.6g %12.6g", i, *_matrix_info(moments[i], hermi=True))
log.debug1("Orthogonalised moments:")
log.debug1(" %4s %12s %12s %12s", "N", "norm", "min(|eig|)", "max(|eig|)")
for i in range(len(moments)):
log.debug1(" %4d %12.6g %12.6g %12.6g", i, *_matrix_info(t[i], hermi=True))
for i in range(niter):
log.info("Iteration %d", i)
b2 = np.zeros((nmo, nmo), dtype=dtype)
for j in range(i+2):
for l in range(i+1):
b2 += np.linalg.multi_dot((v[i, l].T.conj(), t[j+l+1], v[i, j-1]))
b2 -= np.dot(a[i], a[i])
if i:
b2 -= np.dot(b[i-1], b[i-1])
b[i] = mat_sqrt(b2, hermi=True)
binv = mat_isqrt(b2, hermi=True)
for j in range(i+2):
r = (
+ v[i, j-1]
- np.dot(v[i, j], a[i])
- np.dot(v[i-1, j], b[i-1])
)
v[i+1, j] = np.dot(r, binv)
for j in range(i+2):
for l in range(i+2):
a[i+1] += np.linalg.multi_dot((v[i+1, l].T.conj(), t[j+l+1], v[i+1, j]))
log.debug1(" %4s %12s %12s %12s", "mat", "norm", "min(|eig|)", "max(|eig|)")
log.debug1(" %4s %12.6g %12.6g %12.6g", "B^2", *_matrix_info(b2))
log.debug1(" %4s %12.6g %12.6g %12.6g", "B", *_matrix_info(b[i]))
log.debug1(" %4s %12.6g %12.6g %12.6g", "B^-1", *_matrix_info(binv))
log.debug1(" %4s %12.6g %12.6g %12.6g", "A", *_matrix_info(a[i+1]))
biorth_error = 0.0
for j in range(i+2):
x = np.zeros_like(v[0, 0])
for k in range(i+2):
for l in range(i+2):
x += np.linalg.multi_dot((v[i+1, l].T.conj(), t[k+l], v[j, k]))
biorth_error = max(biorth_error, np.max(np.abs(x - np.eye(nmo)*((i+1)==j))))
log.info(" Error in biorthogonality: %12.6g", biorth_error)
return a, b
[docs]
def block_lanczos_nosymm(gfccsd, moments, verbose=None):
"""Non-Hermitian block Lanczos solver, returns a set of poles that
best reproduce the inputted moments.
Args:
gfccsd : MomGFCCSD
GF-CCSD object
moments : ndarray (2*niter+2, n, n)
Array of moments with which the resulting poles should
be consistent with.
Kwargs:
verbose : int
Level of verbosity.
Returns:
a : ndarray (niter+1, n, n)
On-diagonal blocks of the block tridiagonal Hamiltonian.
b : ndarray (niter, n, n)
Upper off-diagonal blocks of the block tridiagonal
Hamiltonian.
c : ndarray (niter, n, n)
Lower off-diagonal blocks of the block tridiagonal
Hamiltonian.
"""
log = logger.new_logger(gfccsd, verbose)
log.debug1("block_lanczos_nosymm: %d moments", len(moments))
nmo = gfccsd.nmo
niter = (len(moments) - 2) // 2
dtype = np.complex128
a = np.zeros((niter+1, nmo, nmo), dtype=dtype)
b = np.zeros((niter, nmo, nmo), dtype=dtype)
c = np.zeros((niter, nmo, nmo), dtype=dtype)
t = np.zeros((len(moments), nmo, nmo), dtype=dtype)
v = defaultdict(lambda: np.zeros((nmo, nmo), dtype=dtype))
w = defaultdict(lambda: np.zeros((nmo, nmo), dtype=dtype))
v[0, 0] = np.eye(nmo).astype(dtype)
w[0, 0] = np.eye(nmo).astype(dtype)
orth = mat_isqrt(moments[0])
for i in range(len(moments)):
t[i] = np.linalg.multi_dot((orth, moments[i], orth))
a[0] = t[1]
log.debug1("Raw moments:")
log.debug1(" %4s %12s %12s %12s", "N", "norm", "min(|eig|)", "max(|eig|)")
for i in range(len(moments)):
log.debug1(" %4d %12.6g %12.6g %12.6g", i, *_matrix_info(moments[i]))
log.debug1("Orthogonalised moments:")
log.debug1(" %4s %12s %12s %12s", "N", "norm", "min(|eig|)", "max(|eig|)")
for i in range(len(moments)):
log.debug1(" %4d %12.6g %12.6g %12.6g", i, *_matrix_info(t[i]))
for i in range(niter):
log.info("Iteration %d", i)
b2 = np.zeros((nmo, nmo), dtype=dtype)
c2 = np.zeros((nmo, nmo), dtype=dtype)
for j in range(i+2):
for l in range(i+1):
b2 += np.linalg.multi_dot((w[i, l], t[j+l+1], v[i, j-1]))
c2 += np.linalg.multi_dot((w[i, j-1], t[j+l+1], v[i, l]))
b2 -= np.dot(a[i], a[i])
c2 -= np.dot(a[i], a[i])
if i:
b2 -= np.dot(c[i-1], c[i-1])
c2 -= np.dot(b[i-1], b[i-1])
b[i] = mat_sqrt(b2)
c[i] = mat_sqrt(c2)
binv = mat_isqrt(b2)
cinv = mat_isqrt(c2)
for j in range(i+2):
r = (
+ v[i, j-1]
- np.dot(v[i, j], a[i])
- np.dot(v[i-1, j], b[i-1])
)
v[i+1, j] = np.dot(r, cinv)
s = (
+ w[i, j-1]
- np.dot(a[i], w[i, j])
- np.dot(c[i-1], w[i-1, j])
)
w[i+1, j] = np.dot(binv, s)
for j in range(i+2):
for l in range(i+2):
a[i+1] += np.linalg.multi_dot((w[i+1, l], t[j+l+1], v[i+1, j]))
log.debug1(" %4s %12s %12s %12s", "mat", "norm", "min(|eig|)", "max(|eig|)")
log.debug1(" %4s %12.6g %12.6g %12.6g", "B^2", *_matrix_info(b2))
log.debug1(" %4s %12.6g %12.6g %12.6g", "B", *_matrix_info(b[i]))
log.debug1(" %4s %12.6g %12.6g %12.6g", "B^-1", *_matrix_info(binv))
log.debug1(" %4s %12.6g %12.6g %12.6g", "C^2", *_matrix_info(c2))
log.debug1(" %4s %12.6g %12.6g %12.6g", "C", *_matrix_info(c[i]))
log.debug1(" %4s %12.6g %12.6g %12.6g", "C^-1", *_matrix_info(cinv))
log.debug1(" %4s %12.6g %12.6g %12.6g", "A", *_matrix_info(a[i+1]))
biorth_error = 0.0
for j in range(i+2):
x = np.zeros_like(v[0, 0])
y = np.zeros_like(v[0, 0])
for k in range(i+2):
for l in range(i+2):
x += np.linalg.multi_dot((w[i+1, l], t[k+l], v[j, k]))
y += np.linalg.multi_dot((w[j, l], t[k+l], v[i+1, k]))
biorth_error = max(biorth_error, np.max(np.abs(x - np.eye(nmo)*((i+1)==j))))
biorth_error = max(biorth_error, np.max(np.abs(y - np.eye(nmo)*((i+1)==j))))
log.info(" Error in biorthogonality: %12.6g", biorth_error)
return a, b, c
def _kd(n, i):
v = np.zeros((n,))
v[i] = 1.0
return v
[docs]
def contract_ket_hole(gfccsd, eom, t1, t2, v, orb):
r"""Contract a vector with \bar{a}^\dagger_p |\Psi>.
"""
nocc, nvir = t1.shape
if orb < nocc:
return v[orb]
else:
b1 = t1[:, orb-nocc]
b2 = t2[:, :, orb-nocc]
b = eom.amplitudes_to_vector(b1, b2)
return np.dot(v, b)
[docs]
def build_ket_hole(gfccsd, eom, t1, t2, orb):
r"""Build \bar{a}^\dagger_p |\Psi>.
"""
nocc, nvir = t1.shape
if orb < nocc:
b1 = np.eye(nocc)[orb]
b2 = np.zeros((nocc, nocc, nvir))
else:
b1 = t1[:, orb-nocc]
b2 = t2[:, :, orb-nocc]
return eom.amplitudes_to_vector(b1, b2)
[docs]
def build_bra_hole(gfccsd, eom, t1, t2, l1, l2, orb):
"""Get the first- and second-order contributions to the left-hand
transformed vector for a given orbital for the hole part of the
Green's function.
"""
nocc, nvir = t1.shape
if orb < nocc:
e1 = _kd(nocc, orb)
e1 -= lib.einsum("ie,e->i", l1, t1[orb])
tmp = t2[orb] * 2.0
tmp -= t2[orb].swapaxes(1, 2)
e1 -= lib.einsum("imef,mef->i", l2, tmp)
tmp = -lib.einsum("ijea,e->ija", l2, t1[orb])
e2 = 2.0 * tmp
e2 -= tmp.swapaxes(0, 1)
tmp = lib.einsum("ja,i->ija", l1, _kd(nocc, orb))
e2 += tmp * 2.0
e2 -= tmp.swapaxes(0, 1)
else:
e1 = l1[:, orb-nocc].copy()
e2 = l2[:, :, orb-nocc] * 2.0
e2 -= l2[:, :, :, orb-nocc]
return eom.amplitudes_to_vector(e1, e2)
[docs]
def contract_ket_part(gfccsd, eom, t1, t2, v, orb):
r"""Contract a vector with \bar{a}_p |\Psi>.
"""
nocc, nvir = t1.shape
if orb < nocc:
b1 = t1[orb]
b2 = t2[orb]
b = eom.amplitudes_to_vector(b1, b2)
return np.dot(v, b)
else:
return -v[orb-nocc]
[docs]
def build_ket_part(gfccsd, eom, t1, t2, orb):
r"""Build \bar{a}_p |\Psi>.
"""
nocc, nvir = t1.shape
if orb < nocc:
b1 = t1[orb]
b2 = t2[orb]
else:
b1 = -np.eye(nvir)[orb-nocc]
b2 = np.zeros((nocc, nvir, nvir))
return eom.amplitudes_to_vector(b1, b2)
[docs]
def build_bra_part(gfccsd, eom, t1, t2, l1, l2, orb):
"""Get the first- and second-order contributions to the left-hand
transformed vector for a given orbital for the particle part of the
Green's function.
"""
nocc, nvir = t1.shape
if orb < nocc:
e1 = -l1[orb]
e2 = -l2[orb] * 2.0
e2 += l2[:, orb]
else:
e1 = _kd(nvir, orb-nocc)
e1 -= lib.einsum("mb,m->b", l1, t1[:, orb-nocc])
tmp = t2[:, :, :, orb-nocc] * 2.0
tmp -= t2[:, :, orb-nocc]
e1 -= lib.einsum("kmeb,kme->b", l2, tmp)
tmp = -lib.einsum("ikba,k->iab", l2, t1[:, orb-nocc])
e2 = tmp * 2.0
e2 -= tmp.swapaxes(1, 2)
tmp = lib.einsum("ib,a->iab", l1, _kd(nvir, orb-nocc))
e2 += tmp * 2.0
e2 -= tmp.swapaxes(1, 2)
return eom.amplitudes_to_vector(e1, e2)
[docs]
class MomGFCCSD(lib.StreamObject):
"""Green's function coupled cluster singles and doubles using the
moment-resolved solver.
Attributes:
verbose : int
Print level. Default value equals to :class:`Mole.verbose`.
niter : tuple of (int, int)
Number of block Lanczos iterations for occupied and virtual
sectors. If either are `None` then said sector will not be
computed.
weight_tol : float
Threshold for weight in the physical space to consider a
pole an ionisation or removal event. Default value is 1e-1.
hermi_moments : bool
Whether to Hermitise the moments, default value is False.
hermi_solver : obol
Whether to use the real-valued, symmetric block Lanczos
solver, default value is False.
Results:
eh : ndarray
Energies of the compressed hole Green's function
vh : tuple of ndarray
Left- and right-hand transition amplitudes of the compressed
hole Green's function
ep : ndarray
Energies of the compressed particle Green's function
vp : tuple of ndarray
Left- and right-hand transition amplitudes of the compressed
particle Green's function
"""
_keys = set((
'verbose', 'stdout', 'niter', 'weight_tol',
'hermi_moments', 'hermi_solver', 'eh', 'ep', 'vh', 'vp', 'chkfile',
))
def __init__(self, mycc, niter=(2, 2)):
self._cc = mycc
self.verbose = mycc.verbose
self.stdout = mycc.stdout
if isinstance(mycc, cc.uccsd.UCCSD):
raise NotImplementedError("MomGFCCSD for unrestricted CCSD")
if isinstance(niter, int):
self.niter = (niter, niter)
else:
self.niter = niter
self.weight_tol = 1e-1
self.hermi_moments = False
self.hermi_solver = False
self.eh = None
self.ep = None
self.vh = None
self.vp = None
self._t1 = None
self._t2 = None
self._l1 = None
self._l2 = None
self.chkfile = self._cc.chkfile
[docs]
def dump_flags(self, verbose=None):
log = logger.new_logger(self, verbose)
log.info("")
log.info("******** %s ********", self.__class__)
log.info("niter = %s", self.niter)
log.info("nmo = %s", self.nmo)
log.info("nocc = %s", self.nocc)
log.info("weight_tol = %s", self.weight_tol)
log.info("hermi_moments = %s", self.hermi_moments)
log.info("hermi_solver = %s", self.hermi_solver)
log.info("chkfile = %s", self.chkfile)
def _finalize(self):
self.ipgfccsd()
self.eagfccsd()
return self
[docs]
def reset(self, mol=None):
self._cc.reset(mol)
return self
@property
def eomip_method(self):
return self._cc.eomip_method()
@property
def eomea_method(self):
return self._cc.eomea_method()
build_bra_hole = build_bra_hole
build_bra_part = build_bra_part
contract_ket_hole = contract_ket_hole
contract_ket_part = contract_ket_part
[docs]
def make_imds(self, eris=None, ip=True, ea=True):
"""Build EOM intermediates.
"""
imds = cc.eom_rccsd._IMDS(self._cc, eris=eris)
if ip:
imds.make_ip()
if ea:
imds.make_ea()
return imds
[docs]
def build_hole_moments(self, t1=None, t2=None, l1=None, l2=None, imds=None, niter=None):
"""Build moments of the hole (IP-EOM-CCSD) Green's function.
"""
if t1 is None:
t1 = self._cc.t1
if t2 is None:
t2 = self._cc.t2
if l1 is None:
l1 = self._cc.l1
if l2 is None:
l2 = self._cc.l2
if niter is None:
niter = self.niter[0]
nmom = 2 * niter + 2
moments = np.zeros((nmom, self.nmo, self.nmo))
cput0 = (logger.process_clock(), logger.perf_counter())
eom = self.eomip_method()
if imds is None:
imds = self.make_imds(ea=False)
diag = eom.get_diag(imds)
for p in mpi_helper.nrange(self.nmo):
ket = self.build_bra_hole(eom, t1, t2, l1, l2, p)
for n in range(nmom):
for q in range(self.nmo):
moments[n, q, p] += self.contract_ket_hole(eom, t1, t2, ket, q)
if (n+1) != nmom:
ket = -eom.l_matvec(ket, imds, diag)
mpi_helper.barrier()
moments = mpi_helper.allreduce(moments)
logger.timer(self, "IP-EOM-CCSD moments", *cput0)
return moments
[docs]
def build_part_moments(self, t1=None, t2=None, l1=None, l2=None, imds=None, niter=None):
"""Build moments of the particle (EA-EOM-CCSD) Green's function.
"""
if t1 is None:
t1 = self._cc.t1
if t2 is None:
t2 = self._cc.t2
if l1 is None:
l1 = self._cc.l1
if l2 is None:
l2 = self._cc.l2
if niter is None:
niter = self.niter[1]
nmom = 2 * niter + 2
moments = np.zeros((nmom, self.nmo, self.nmo))
cput0 = (logger.process_clock(), logger.perf_counter())
eom = self.eomea_method()
if imds is None:
imds = self.make_imds(ip=False)
diag = eom.get_diag(imds)
for p in mpi_helper.nrange(self.nmo):
ket = self.build_bra_part(eom, t1, t2, l1, l2, p)
for n in range(nmom):
for q in range(self.nmo):
moments[n, q, p] -= self.contract_ket_part(eom, t1, t2, ket, q)
if (n+1) != nmom:
ket = eom.l_matvec(ket, imds, diag)
mpi_helper.barrier()
moments = mpi_helper.allreduce(moments)
logger.timer(self, "EA-EOM-CCSD moments", *cput0)
return moments
[docs]
def make_rdm1(self, ao_repr=False, eris=None, imds=None):
"""Build the first-order reduced density matrix at the CCSD
level using the zeroth-order moment of the hole part of the
CCSD Green's function.
"""
if imds is None:
imds = self.make_imds(eris=eris, ea=False)
dm1 = self.build_hole_moments(imds=imds, niter=0)[0]
dm1 = dm1 + dm1.T.conj()
if ao_repr:
mo = self._cc.mo_coeff
dm1 = np.linalg.multi_dot((mo, dm1, mo.T.conj()))
return dm1
[docs]
def kernel(self, **kwargs):
eh, vh, ep, vp = kernel(self, **kwargs)
self.eh = eh
self.vh = vh
self.ep = ep
self.vp = vp
self._finalize()
return eh, vh, ep, vp
[docs]
def dump_chk(self, chkfile=None, key="gfccsd"):
if chkfile is None:
chkfile = self.chkfile
lib.chkfile.dump(chkfile, key+"/eh", self.eh)
lib.chkfile.dump(chkfile, key+"/vh_left", self.vh[0])
lib.chkfile.dump(chkfile, key+"/vh_right", self.vh[1])
lib.chkfile.dump(chkfile, key+"/ep", self.ep)
lib.chkfile.dump(chkfile, key+"/vp_left", self.vp[0])
lib.chkfile.dump(chkfile, key+"/vp_right", self.vp[1])
lib.chkfile.dump(chkfile, key+"/niter", np.array(self.niter))
return self
[docs]
def update_from_chk_(self, chkfile=None, key="gfccsd"):
if chkfile is None:
chkfile = self.chkfile
self.eh = lib.chkfile.load(chkfile, key+"/eh")
self.vh = (
lib.chkfile.load(chkfile, key+"/vh_left"),
lib.chkfile.load(chkfile, key+"/vh_right"),
)
self.ep = lib.chkfile.load(chkfile, key+"/ep")
self.vp = (
lib.chkfile.load(chkfile, key+"/vp_left"),
lib.chkfile.load(chkfile, key+"/vp_right"),
)
self.niter = tuple(lib.chkfile.load(chkfile, key+"/niter"))
update = update_from_chk = update_from_chk_
[docs]
def ipgfccsd(self, nroots=5):
"""Print and return ionisation potentials.
"""
eh, (vh, uh) = self.eh, self.vh
mask = np.abs(np.sum(vh * uh.conj(), axis=0)) > self.weight_tol
mask = np.arange(mask.size)[mask][::-1]
e_ip = -eh[mask]
v_ip, u_ip = vh[:, mask], uh[:, mask]
nroots = min(nroots, len(e_ip))
logger.note(self, " %s %s %16s %10s", "", "", "Energy", "Weight")
for n in range(nroots):
qpwt = np.abs(np.sum(v_ip[:, n] * u_ip[:, n].conj())).real
warn = ""
if np.abs(e_ip[n].imag) > 1e-8:
warn += "(Warning: imag part: %.6g)" % e_ip[n].imag
logger.note(self, " %2s %2d %16.10g %10.6g %s" % ("IP", n, e_ip[n].real, qpwt, warn))
if nroots == 1:
return e_ip[0].real, v_ip[:, 0], u_ip[:, 0]
else:
return e_ip.real, v_ip, u_ip
[docs]
def eagfccsd(self, nroots=5):
"""Print and return electron affinities.
"""
ep, (vp, up) = self.ep, self.vp
mask = np.abs(np.sum(vp * up.conj(), axis=0)) > self.weight_tol
e_ea = ep[mask]
v_ea, u_ea = vp[:, mask], up[:, mask]
nroots = min(nroots, len(e_ea))
logger.note(self, " %s %s %16s %10s", "", "", "Energy", "Weight")
for n in range(nroots):
qpwt = np.abs(np.sum(v_ea[:, n] * u_ea[:, n].conj())).real
warn = ""
if np.abs(e_ea[n].imag) > 1e-8:
warn += "(Warning: imag part: %.6g)" % e_ea[n].imag
logger.note(self, " %2s %2d %16.10g %10.6g %s" % ("EA", n, e_ea[n].real, qpwt, warn))
if nroots == 1:
return e_ea[0].real, v_ea[:, 0], u_ea[:, 0]
else:
return e_ea.real, v_ea, u_ea
@property
def nmo(self):
return self._cc.nmo
@property
def nocc(self):
return self._cc.nocc
if __name__ == "__main__":
from pyscf import gto, scf
mol = gto.M(
#atom="O 0 0 0; O 0 0 1",
atom="N 0 0 0; N 0 0 1",
basis="cc-pvdz",
verbose=0,
)
mf = scf.RHF(mol)
mf = mf.run()
ccsd = cc.CCSD(mf)
ccsd = ccsd.run()
ccsd.solve_lambda()
niter = 5
gfcc = MomGFCCSD(ccsd, (niter, niter))
gfcc.kernel()
ip1, vip1 = ccsd.ipccsd(nroots=8)
ip2, vip2, uip2 = gfcc.ipgfccsd(nroots=8)
ea1, vea1 = ccsd.eaccsd(nroots=8)
ea2, vea2, uea2 = gfcc.eagfccsd(nroots=8)
print(" %12s %12s %12s" % ("EOM", "GF", "Error"))
print("IP1 %12.8f %12.8f %12.8f" % (ip1[0],ip2[0],np.abs(ip1[0]-ip2[0])))
print("IP2 %12.8f %12.8f %12.8f" % (ip1[1],ip2[1],np.abs(ip1[1]-ip2[1])))
print("EA1 %12.8f %12.8f %12.8f" % (ea1[0],ea2[0],np.abs(ea1[0]-ea2[0])))
print("EA2 %12.8f %12.8f %12.8f" % (ea1[1],ea2[1],np.abs(ea1[1]-ea2[1])))