def contract_2e(eri, fcivec, norb, nelec, link_index=None, **kwargs):
if isinstance(nelec, (int, numpy.number)):
sz = (nelec % 2) * .5
else:
sz = abs(nelec[0]-nelec[1]) * .5
if ss_value is None:
ss = sz*(sz+1)
else:
ss = ss_value
ci0 = old_contract_2e(eri, fcivec, norb, nelec, link_index, **kwargs)
if ss == 0:
na = int(numpy.sqrt(fcivec.size))
ci0 = pyscf.lib.transpose_sum(ci0.reshape(na,na), inplace=True)
ci0 *= .5
if ss < sz*(sz+1)+.1:
# (S^2-ss_value)|Psi> to shift state other than the lowest state
ci1 = spin_op.contract_ss(fcivec, norb, nelec).reshape(fcivec.shape)
ci1 -= ss * fcivec
else:
# (S^2-ss_value)^2|Psi> to shift states except the given spin.
# It still relies on the quality of initial guess
tmp = spin_op.contract_ss(fcivec, norb, nelec).reshape(fcivec.shape)
tmp -= ss * fcivec
ci1 = -ss * tmp
ci1 += spin_op.contract_ss(tmp, norb, nelec).reshape(fcivec.shape)
tmp = None
ci1 *= shift
ci1 += ci0.reshape(fcivec.shape)
return ci1
def contract_2e(eri, fcivec, norb, nelec, link_index=None, **kwargs):
if ss_value is None:
# (S^2-ss_value)|Psi> to shift state other than the lowest state
if isinstance(nelec, (int, numpy.integer)):
sz = (nelec % 2) * .5
else:
sz = abs(nelec[0]-nelec[1]) * .5
ss = sz*(sz+1)
ci1 = spin_op.contract_ss(fcivec, norb, nelec)
ci1 -= ss * fcivec.reshape(ci1.shape)
else:
# (S^2-ss_value)^2|Psi> to shift states except the given spin.
# It still relies on the quality of initial guess
ss = ss_value
tmp = spin_op.contract_ss(fcivec, norb, nelec)
tmp -= ss * fcivec.reshape(tmp.shape)
ci1 = -ss * tmp
ci1 += spin_op.contract_ss(tmp, norb, nelec)
tmp = None
if ss == 0:
ci1 = pyscf.lib.transpose_sum(ci1, inplace=True) * .5
ci1 *= shift
ci1 += old_contract_2e(eri, fcivec, norb, nelec, link_index, **kwargs)
return ci1
def contract_2e(eri, fcivec, norb, nelec, link_index=None, **kwargs):
if isinstance(nelec, (int, numpy.number)):
sz = (nelec % 2) * .5
else:
sz = abs(nelec[0] - nelec[1]) * .5
if ss_value is None:
ss = sz * (sz + 1)
else:
ss = ss_value
ci0 = old_contract_2e(eri, fcivec, norb, nelec, link_index, **kwargs)
if ss == 0:
na = int(numpy.sqrt(fcivec.size))
ci0 = pyscf.lib.transpose_sum(ci0.reshape(na, na), inplace=True)
ci0 *= .5
if ss < sz * (sz + 1) + .1:
# (S^2-ss_value)|Psi> to shift state other than the lowest state
ci1 = spin_op.contract_ss(fcivec, norb,
nelec).reshape(fcivec.shape)
ci1 -= ss * fcivec
else:
# (S^2-ss_value)^2|Psi> to shift states except the given spin.
# It still relies on the quality of initial guess
tmp = spin_op.contract_ss(fcivec, norb,
nelec).reshape(fcivec.shape)
tmp -= ss * fcivec
ci1 = -ss * tmp
ci1 += spin_op.contract_ss(tmp, norb, nelec)
tmp = None
ci1 *= shift
ci1 += ci0.reshape(fcivec.shape)
return ci1
def spin_square (fci, fcivec, norb, nelec):
ss = 0.0
for ne in product (range (norb+1), repeat=2):
c = fockspace.fock2hilbert (fcivec, norb, ne)
ssc = spin_op.contract_ss (c, norb, ne)
ss += c.conj ().ravel ().dot (ssc.ravel ())
s = np.sqrt(ss+.25) - .5
multip = s*2+1
return ss, multip
def contract_2e(eri, fcivec, norb, nelec, link_index=None, **kwargs):
ci1 = old_contract_2e(eri, fcivec, norb, nelec, link_index, **kwargs)
if isinstance(nelec, (int, numpy.integer)):
sz = (nelec % 2) * .5
else:
sz = abs(nelec[0]-nelec[1]) * .5
ci1 += shift * spin_op.contract_ss(fcivec, norb, nelec)
ci1 -= sz*(sz+1)*shift * fcivec.reshape(ci1.shape)
if isinstance(fciobj, direct_spin0.FCISolver):
ci1 = pyscf.lib.transpose_sum(ci1, inplace=True) * .5
return ci1
def ham(las, h1, h2, ci_fr, idx_root, orbsym=None, wfnsym=None):
mol = las.mol
norb_f = las.ncas_sub
nelec_fr = [[
_unpack_nelec(fcibox._get_nelec(solver, nelecas))
for solver, ix in zip(fcibox.fcisolvers, idx_root) if ix
] for fcibox, nelecas in zip(las.fciboxes, las.nelecas_sub)]
ci, nelec = ci_outer_product(ci_fr, norb_f, nelec_fr)
solver = fci.solver(mol).set(orbsym=orbsym, wfnsym=wfnsym)
norb = sum(norb_f)
h2eff = solver.absorb_h1e(h1, h2, norb, nelec, 0.5)
ham_ci = [solver.contract_2e(h2eff, c, norb, nelec) for c in ci]
s2_ci = [contract_ss(c, norb, nelec) for c in ci]
ham_eff = np.array([[c.ravel().dot(hc.ravel()) for hc in ham_ci]
for c in ci])
s2_eff = np.array([[c.ravel().dot(s2c.ravel()) for s2c in s2_ci]
for c in ci])
ovlp_eff = np.array([[bra.ravel().dot(ket.ravel()) for ket in ci]
for bra in ci])
return ham_eff, s2_eff, ovlp_eff
def contract_ss(self, fcivec, norb, nelec):
from pyscf.fci import spin_op
nelec = _unpack_nelec(nelec, self.spin)
return spin_op.contract_ss(fcivec, norb, nelec)
def contract_ss(self, fcivec, norb, nelec):
from pyscf.fci import spin_op
return spin_op.contract_ss(fcivec, norb, nelec)
def contract_ss(self, fcivec, norb, nelec):
from pyscf.fci import spin_op
return spin_op.contract_ss(fcivec, norb, nelec)
def contract_ss(self, fcivec, norb, nelec):
from pyscf.fci import spin_op
nelec = _unpack_nelec(nelec, self.spin)
return spin_op.contract_ss(fcivec, norb, nelec)
