def solver(mol, singlet=True, symm=None):
if symm is None:
symm = mol.symmetry
if symm:
if singlet:
return direct_spin0_symm.FCISolver(mol)
else:
return direct_spin1_symm.FCISolver(mol)
else:
if singlet:
return direct_spin0.FCISolver(mol)
else:
return direct_spin1.FCISolver(mol)
def solver(mol=None, singlet=False, symm=None):
if mol and symm is None:
symm = mol.symmetry
if symm:
if singlet:
return direct_spin0_symm.FCISolver(mol)
else:
return direct_spin1_symm.FCISolver(mol)
else:
if singlet:
# The code for singlet direct_spin0 sometimes gets error of
# "State not singlet x.xxxxxxe-06" due to numerical issues.
# Calling direct_spin1 is slightly slower but more robust than
# direct_spin0 especially when combining to energy penalty method
# (:func:`fix_spin_`)
return direct_spin0.FCISolver(mol)
else:
return direct_spin1.FCISolver(mol)
for i in range(dm2abba.shape[0]):
dm2abba[:, i, i, :] += dm1b
dm2baab = dm2abba
if reorder:
spinfree_2 = dm2aa + dm2bb + 2 * dm2ab
one_sf, two_sf = find_full_casscf_12rdm(mc.fcisolver, mf.mo_coeff,
'spinfree_TwoRDM.1', norb,
nelec)
assert (numpy.allclose(
two_sf[:n_occorbs, :n_occorbs, :n_occorbs, :n_occorbs],
spinfree_2))
mc2 = mcscf.CASCI(mf, 6, 6)
# mc2.canonicalization = False
mc2.fcisolver = direct_spin1.FCISolver(mol)
emc2, e_cas2, fcivec2 = mc2.kernel()[:3]
#ss_tot = spin_op.spin_square(fcivec2, norb, nelec)[0]
# print 'ss_tot exact: ',ss_tot
(dm1a_, dm1b_), (dm2aa_, dm2ab_,
dm2bb_) = direct_spin1.make_rdm12s(fcivec2,
norb,
nelec,
reorder=False)
#f_dbg = dbg_ss_frac(dm1, dm2, norb, mo_cas, ovlp)
# dm2baab(pq,rs) = <p(beta)* q(alpha) r(alpha)* s(beta)
dm2baab_ = spin_op._make_rdm2_baab(fcivec2, norb, nelec)
# dm2abba(pq,rs) = <q(alpha)* p(beta) s(beta)* r(alpha)
dm2abba_ = spin_op._make_rdm2_abba(fcivec2, norb, nelec)
ss_tot = spin_op.spin_square(fcivec2, norb, nelec)[0]
