#!/usr/bin/env python
# Copyright 2014-2018 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.
'''
FCIDUMP functions (write, read) for real Hamiltonian
'''
import re
from functools import reduce
import numpy
from pyscf import gto
from pyscf import scf
from pyscf import ao2mo
from pyscf import symm
from pyscf import __config__
DEFAULT_FLOAT_FORMAT = getattr(__config__, 'fcidump_float_format', ' %.16g')
TOL = getattr(__config__, 'fcidump_write_tol', 1e-15)
MOLPRO_ORBSYM = getattr(__config__, 'fcidump_molpro_orbsym', False)
# Mapping Pyscf symmetry numbering to Molpro symmetry numbering for each irrep.
# See also pyscf.symm.param.IRREP_ID_TABLE
# https://www.molpro.net/info/current/doc/manual/node36.html
ORBSYM_MAP = {
'D2h': (1, # Ag
4, # B1g
6, # B2g
7, # B3g
8, # Au
5, # B1u
3, # B2u
2), # B3u
'C2v': (1, # A1
4, # A2
2, # B1
3), # B2
'C2h': (1, # Ag
4, # Bg
2, # Au
3), # Bu
'D2' : (1, # A
4, # B1
3, # B2
2), # B3
'Cs' : (1, # A'
2), # A"
'C2' : (1, # A
2), # B
'Ci' : (1, # Ag
2), # Au
'C1' : (1,)
}
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def write_head(fout, nmo, nelec, ms=0, orbsym=None):
if not isinstance(nelec, (int, numpy.number)):
ms = abs(nelec[0] - nelec[1])
nelec = nelec[0] + nelec[1]
fout.write(' &FCI NORB=%4d,NELEC=%2d,MS2=%d,\n' % (nmo, nelec, ms))
if orbsym is not None and len(orbsym) > 0:
fout.write(' ORBSYM=%s\n' % ','.join([str(x) for x in orbsym]))
else:
fout.write(' ORBSYM=%s\n' % ('1,' * nmo))
fout.write(' ISYM=1,\n')
fout.write(' &END\n')
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def write_eri(fout, eri, nmo, tol=TOL, float_format=DEFAULT_FLOAT_FORMAT):
npair = nmo*(nmo+1)//2
output_format = float_format + ' %4d %4d %4d %4d\n'
if eri.size == nmo**4:
eri = ao2mo.restore(8, eri, nmo)
if eri.ndim == 2: # 4-fold symmetry
assert (eri.size == npair**2)
ij = 0
for i in range(nmo):
for j in range(0, i+1):
kl = 0
for k in range(0, nmo):
for l in range(0, k+1):
if abs(eri[ij,kl]) > tol:
fout.write(output_format % (eri[ij,kl], i+1, j+1, k+1, l+1))
kl += 1
ij += 1
else: # 8-fold symmetry
assert (eri.size == npair*(npair+1)//2)
ij = 0
ijkl = 0
for i in range(nmo):
for j in range(0, i+1):
kl = 0
for k in range(0, i+1):
for l in range(0, k+1):
if ij >= kl:
if abs(eri[ijkl]) > tol:
fout.write(output_format % (eri[ijkl], i+1, j+1, k+1, l+1))
ijkl += 1
kl += 1
ij += 1
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def write_hcore(fout, h, nmo, tol=TOL, float_format=DEFAULT_FLOAT_FORMAT):
h = h.reshape(nmo,nmo)
output_format = float_format + ' %4d %4d 0 0\n'
for i in range(nmo):
for j in range(0, i+1):
if abs(h[i,j]) > tol:
fout.write(output_format % (h[i,j], i+1, j+1))
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def from_chkfile(filename, chkfile, tol=TOL, float_format=DEFAULT_FLOAT_FORMAT,
molpro_orbsym=MOLPRO_ORBSYM, orbsym=None):
'''Read SCF results from PySCF chkfile and transform 1-electron,
2-electron integrals using the SCF orbitals. The transformed integrals is
written to FCIDUMP
Kwargs:
molpro_orbsym (bool): Whether to dump the orbsym in Molpro orbsym
convention as documented in
https://www.molpro.net/info/current/doc/manual/node36.html
'''
mol, scf_rec = scf.chkfile.load_scf(chkfile)
mo_coeff = numpy.array(scf_rec['mo_coeff'])
nmo = mo_coeff.shape[1]
s = reduce(numpy.dot, (mo_coeff.conj().T, mol.intor_symmetric('int1e_ovlp'), mo_coeff))
if abs(s - numpy.eye(nmo)).max() > 1e-6:
# Not support the chkfile from pbc calculation
raise RuntimeError('Non-orthogonal orbitals found in chkfile')
if mol.symmetry:
orbsym = symm.label_orb_symm(mol, mol.irrep_id,
mol.symm_orb, mo_coeff, check=False)
from_mo(mol, filename, mo_coeff, orbsym=orbsym, tol=tol,
float_format=float_format, molpro_orbsym=molpro_orbsym,
ms=mol.spin)
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def from_integrals(filename, h1e, h2e, nmo, nelec, nuc=0, ms=0, orbsym=None,
tol=TOL, float_format=DEFAULT_FLOAT_FORMAT):
'''Convert the given 1-electron and 2-electron integrals to FCIDUMP format'''
with open(filename, 'w') as fout:
write_head(fout, nmo, nelec, ms, orbsym)
write_eri(fout, h2e, nmo, tol=tol, float_format=float_format)
write_hcore(fout, h1e, nmo, tol=tol, float_format=float_format)
output_format = float_format + ' 0 0 0 0\n'
fout.write(output_format % nuc)
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def from_mo(mol, filename, mo_coeff, orbsym=None,
tol=TOL, float_format=DEFAULT_FLOAT_FORMAT,
molpro_orbsym=MOLPRO_ORBSYM, ms=0):
'''Use the given MOs to transform the 1-electron and 2-electron integrals
then dump them to FCIDUMP.
Kwargs:
molpro_orbsym (bool): Whether to dump the orbsym in Molpro orbsym
convention as documented in
https://www.molpro.net/info/current/doc/manual/node36.html
'''
if getattr(mol, '_mesh', None):
raise NotImplementedError('PBC system')
if orbsym is None:
orbsym = getattr(mo_coeff, 'orbsym', None)
if molpro_orbsym and orbsym is not None:
orbsym = [ORBSYM_MAP[mol.groupname][i] for i in orbsym]
h1ao = scf.hf.get_hcore(mol)
h1e = reduce(numpy.dot, (mo_coeff.T, h1ao, mo_coeff))
eri = ao2mo.full(mol, mo_coeff, verbose=0)
nuc = mol.energy_nuc()
from_integrals(filename, h1e, eri, h1e.shape[0], mol.nelec, nuc, ms, orbsym,
tol, float_format)
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def from_scf(mf, filename, tol=TOL, float_format=DEFAULT_FLOAT_FORMAT,
molpro_orbsym=MOLPRO_ORBSYM):
'''Use the given SCF object to transform the 1-electron and 2-electron
integrals then dump them to FCIDUMP.
Kwargs:
molpro_orbsym (bool): Whether to dump the orbsym in Molpro orbsym
convention as documented in
https://www.molpro.net/info/current/doc/manual/node36.html
'''
mol = mf.mol
mo_coeff = mf.mo_coeff
assert mo_coeff.dtype == numpy.double
h1e = reduce(numpy.dot, (mo_coeff.T, mf.get_hcore(), mo_coeff))
if mf._eri is None:
if getattr(mf, 'exxdiv', None): # PBC system
eri = mf.with_df.ao2mo(mo_coeff)
else:
eri = ao2mo.full(mf.mol, mo_coeff)
else: # Handle cached integrals or customized systems
eri = ao2mo.full(mf._eri, mo_coeff)
orbsym = getattr(mo_coeff, 'orbsym', None)
if molpro_orbsym and orbsym is not None:
orbsym = [ORBSYM_MAP[mol.groupname][i] for i in orbsym]
nuc = mf.energy_nuc()
from_integrals(filename, h1e, eri, h1e.shape[0], mf.mol.nelec, nuc, 0, orbsym,
tol, float_format)
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def from_mcscf(mc, filename, tol=TOL, float_format=DEFAULT_FLOAT_FORMAT,
molpro_orbsym=MOLPRO_ORBSYM):
'''Use the given MCSCF object to obtain the CAS 1-electron and 2-electron
integrals and dump them to FCIDUMP.
Kwargs:
tol (float): Threshold for writing elements to FCIDUMP
float_format (str): Float format for writing elements to FCIDUMP
molpro_orbsym (bool): Whether to dump the orbsym in Molpro orbsym
convention as documented in
https://www.molpro.net/manual/doku.php?id=general_program_structure#symmetry
'''
mol = mc.mol
mo_coeff = mc.mo_coeff
assert mo_coeff.dtype == numpy.double
h1eff, ecore = mc.get_h1eff()
h2eff = mc.get_h2eff()
orbsym = getattr(mo_coeff, 'orbsym', None)
if orbsym is not None:
orbsym = orbsym[mc.ncore:mc.ncore + mc.ncas]
if molpro_orbsym and orbsym is not None:
orbsym = [ORBSYM_MAP[mol.groupname][i] for i in orbsym]
nelecas = mc.nelecas[0] + mc.nelecas[1]
ms = abs(mc.nelecas[0] - mc.nelecas[1])
from_integrals(filename, h1eff, h2eff, mc.ncas, nelecas, nuc=ecore, ms=ms,
orbsym=orbsym, tol=tol, float_format=float_format)
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def read(filename, molpro_orbsym=MOLPRO_ORBSYM, verbose=True):
'''Parse FCIDUMP. Return a dictionary to hold the integrals and
parameters with keys: H1, H2, ECORE, NORB, NELEC, MS, ORBSYM, ISYM
Kwargs:
molpro_orbsym (bool): Whether the orbsym in the FCIDUMP file is in
Molpro orbsym convention as documented in::
https://www.molpro.net/info/current/doc/manual/node36.html
In return, orbsym is converted to pyscf symmetry convention
verbose (bool): Whether to print debugging information
'''
if verbose:
print('Parsing %s' % filename)
finp = open(filename, 'r')
data = []
for i in range(10):
line = finp.readline().upper()
data.append(line)
if '&END' in line:
break
else:
raise RuntimeError('Problematic FCIDUMP header')
result = {}
tokens = ','.join(data).replace('&FCI', '').replace('&END', '')
tokens = tokens.replace(' ', '').replace('\n', '').replace(',,', ',')
for token in re.split(',(?=[a-zA-Z])', tokens):
key, val = token.split('=')
if key in ('NORB', 'NELEC', 'MS2', 'ISYM'):
result[key] = int(val.replace(',', ''))
elif key in ('ORBSYM',):
result[key] = [int(x) for x in val.replace(',', ' ').split()]
else:
result[key] = val
# Convert to Molpro orbsym convert_orbsym
if 'ORBSYM' in result:
if molpro_orbsym:
# Guess which point group the orbsym belongs to. FCIDUMP does not
# save the point group information, the guess might be wrong if
# the high symmetry numbering of orbitals are not presented.
orbsym = result['ORBSYM']
if max(orbsym) > 4:
result['ORBSYM'] = [ORBSYM_MAP['D2h'].index(i) for i in orbsym]
elif max(orbsym) > 2:
# Fortunately, without molecular orientation, B2 and B3 in D2
# are not distinguishable
result['ORBSYM'] = [ORBSYM_MAP['C2v'].index(i) for i in orbsym]
elif max(orbsym) == 2:
result['ORBSYM'] = [i-1 for i in orbsym]
elif max(orbsym) == 1:
result['ORBSYM'] = [0] * len(orbsym)
else:
raise RuntimeError('Unknown orbsym')
elif min(result['ORBSYM']) < 0:
raise RuntimeError('Unknown orbsym convention')
norb = result['NORB']
norb_pair = norb * (norb+1) // 2
h1e = numpy.zeros((norb,norb))
h2e = numpy.zeros(norb_pair*(norb_pair+1)//2)
dat = finp.readline().split()
while dat:
i, j, k, l = [int(x) for x in dat[1:5]]
if k != 0:
if i >= j:
ij = i * (i-1) // 2 + j-1
else:
ij = j * (j-1) // 2 + i-1
if k >= l:
kl = k * (k-1) // 2 + l-1
else:
kl = l * (l-1) // 2 + k-1
if ij >= kl:
h2e[ij*(ij+1)//2+kl] = float(dat[0])
else:
h2e[kl*(kl+1)//2+ij] = float(dat[0])
elif k == 0:
if j != 0:
h1e[i-1,j-1] = float(dat[0])
else:
result['ECORE'] = float(dat[0])
dat = finp.readline().split()
idx, idy = numpy.tril_indices(norb, -1)
if numpy.linalg.norm(h1e[idy,idx]) == 0:
h1e[idy,idx] = h1e[idx,idy]
elif numpy.linalg.norm(h1e[idx,idy]) == 0:
h1e[idx,idy] = h1e[idy,idx]
result['H1'] = h1e
result['H2'] = h2e
finp.close()
return result
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def to_scf(filename, molpro_orbsym=MOLPRO_ORBSYM, mf=None, **kwargs):
'''Use the Hamiltonians defined by FCIDUMP to build an SCF object'''
ctx = read(filename, molpro_orbsym)
mol = gto.M()
mol.nelectron = ctx['NELEC']
mol.spin = ctx['MS2']
norb = mol.nao = ctx['NORB']
if 'ECORE' in ctx:
mol.energy_nuc = lambda *args: ctx['ECORE']
mol.incore_anyway = True
if 'ORBSYM' in ctx:
mol.symmetry = True
mol.groupname = 'N/A'
orbsym = numpy.asarray(ctx['ORBSYM'])
mol.irrep_id = list(set(orbsym))
mol.irrep_name = [('IR%d' % ir) for ir in mol.irrep_id]
so = numpy.eye(norb)
mol.symm_orb = []
for ir in mol.irrep_id:
mol.symm_orb.append(so[:,orbsym==ir])
if mf is None:
mf = mol.RHF(**kwargs)
else:
mf.mol = mol
h1 = ctx['H1']
idx, idy = numpy.tril_indices(norb, -1)
if h1[idx,idy].max() == 0:
h1[idx,idy] = h1[idy,idx]
else:
h1[idy,idx] = h1[idx,idy]
mf.get_hcore = lambda *args: h1
mf.get_ovlp = lambda *args: numpy.eye(norb)
mf._eri = ctx['H2']
return mf
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def scf_from_fcidump(mf, filename, molpro_orbsym=MOLPRO_ORBSYM):
'''Update the SCF object with the quantities defined in FCIDUMP file'''
return to_scf(filename, molpro_orbsym, mf)
scf.hf.SCF.from_fcidump = scf_from_fcidump
if __name__ == '__main__':
import argparse
parser = argparse.ArgumentParser(description='Convert chkfile to FCIDUMP')
parser.add_argument('chkfile', help='pyscf chkfile')
parser.add_argument('fcidump', help='FCIDUMP file')
args = parser.parse_args()
# fcidump.py chkfile output
from_chkfile(args.fcidump, args.chkfile)