def from_fcivec(ci0, norb, nelec, frozen=0):
'''Extract CISD coefficients from FCI coefficients'''
if frozen is not 0:
raise NotImplementedError
if isinstance(nelec, (int, numpy.number)):
nelecb = nelec//2
neleca = nelec - nelecb
else:
neleca, nelecb = nelec
norba = norbb = norb
nocc = nocca, noccb = neleca, nelecb
nvira = norba - nocca
nvirb = norbb - noccb
t1addra, t1signa = cisd.tn_addrs_signs(norba, nocca, 1)
t1addrb, t1signb = cisd.tn_addrs_signs(norbb, noccb, 1)
na = cistring.num_strings(norba, nocca)
nb = cistring.num_strings(norbb, noccb)
ci0 = ci0.reshape(na,nb)
c0 = ci0[0,0]
c1a = (ci0[t1addra,0] * t1signa).reshape(nocca,nvira)
c1b = (ci0[0,t1addrb] * t1signb).reshape(noccb,nvirb)
c2ab = numpy.einsum('i,j,ij->ij', t1signa, t1signb, ci0[t1addra[:,None],t1addrb])
c2ab = c2ab.reshape(nocca,nvira,noccb,nvirb).transpose(0,2,1,3)
t2addra, t2signa = cisd.tn_addrs_signs(norba, nocca, 2)
t2addrb, t2signb = cisd.tn_addrs_signs(norbb, noccb, 2)
c2aa = (ci0[t2addra,0] * t2signa).reshape(nocca*(nocca-1)//2, nvira*(nvira-1)//2)
c2aa = _unpack_4fold(c2aa, nocca, nvira)
c2bb = (ci0[0,t2addrb] * t2signb).reshape(noccb*(noccb-1)//2, nvirb*(nvirb-1)//2)
c2bb = _unpack_4fold(c2bb, noccb, nvirb)
return amplitudes_to_cisdvec(c0, (c1a,c1b), (c2aa,c2ab,c2bb))
def from_fcivec(ci0, norb, nelec, frozen=0):
'''Extract CISD coefficients from FCI coefficients'''
if frozen is not 0:
raise NotImplementedError
if isinstance(nelec, (int, numpy.number)):
nelecb = nelec//2
neleca = nelec - nelecb
else:
neleca, nelecb = nelec
norba = norbb = norb
nocc = nocca, noccb = neleca, nelecb
nvira = norba - nocca
nvirb = norbb - noccb
t1addra, t1signa = cisd.tn_addrs_signs(norba, nocca, 1)
t1addrb, t1signb = cisd.tn_addrs_signs(norbb, noccb, 1)
na = cistring.num_strings(norba, nocca)
nb = cistring.num_strings(norbb, noccb)
ci0 = ci0.reshape(na,nb)
c0 = ci0[0,0]
c1a = (ci0[t1addra,0] * t1signa).reshape(nocca,nvira)
c1b = (ci0[0,t1addrb] * t1signb).reshape(noccb,nvirb)
c2ab = numpy.einsum('i,j,ij->ij', t1signa, t1signb, ci0[t1addra[:,None],t1addrb])
c2ab = c2ab.reshape(nocca,nvira,noccb,nvirb).transpose(0,2,1,3)
t2addra, t2signa = cisd.tn_addrs_signs(norba, nocca, 2)
t2addrb, t2signb = cisd.tn_addrs_signs(norbb, noccb, 2)
c2aa = (ci0[t2addra,0] * t2signa).reshape(nocca*(nocca-1)//2, nvira*(nvira-1)//2)
c2aa = _unpack_4fold(c2aa, nocca, nvira)
c2bb = (ci0[0,t2addrb] * t2signb).reshape(noccb*(noccb-1)//2, nvirb*(nvirb-1)//2)
c2bb = _unpack_4fold(c2bb, noccb, nvirb)
return amplitudes_to_cisdvec(c0, (c1a,c1b), (c2aa,c2ab,c2bb))
def cisdvec_to_amplitudes(civec, nmo, nocc, copy=True):
nvir = nmo - nocc
c0 = civec[0]
cp = lambda x: (x.copy() if copy else x)
c1 = cp(civec[1:nocc * nvir + 1].reshape(nocc, nvir))
c2 = ccsd._unpack_4fold(civec[nocc * nvir + 1:], nocc, nvir)
return c0, c1, c2
def cisdvec_to_amplitudes(civec, nmo, nocc):
norba, norbb = nmo
nocca, noccb = nocc
nvira = norba - nocca
nvirb = norbb - noccb
nooa = nocca * (nocca-1) // 2
nvva = nvira * (nvira-1) // 2
noob = noccb * (noccb-1) // 2
nvvb = nvirb * (nvirb-1) // 2
size = (1, nocca*nvira, noccb*nvirb, nocca*noccb*nvira*nvirb,
nooa*nvva, noob*nvvb)
loc = numpy.cumsum(size)
c0 = civec[0]
c1a = civec[loc[0]:loc[1]].reshape(nocca,nvira)
c1b = civec[loc[1]:loc[2]].reshape(noccb,nvirb)
c2ab = civec[loc[2]:loc[3]].reshape(nocca,noccb,nvira,nvirb)
c2aa = _unpack_4fold(civec[loc[3]:loc[4]], nocca, nvira)
c2bb = _unpack_4fold(civec[loc[4]:loc[5]], noccb, nvirb)
return c0, (c1a,c1b), (c2aa,c2ab,c2bb)
def cisdvec_to_amplitudes(civec, nmo, nocc):
norba, norbb = nmo
nocca, noccb = nocc
nvira = norba - nocca
nvirb = norbb - noccb
nooa = nocca * (nocca-1) // 2
nvva = nvira * (nvira-1) // 2
noob = noccb * (noccb-1) // 2
nvvb = nvirb * (nvirb-1) // 2
size = (1, nocca*nvira, noccb*nvirb, nocca*noccb*nvira*nvirb,
nooa*nvva, noob*nvvb)
loc = numpy.cumsum(size)
c0 = civec[0]
c1a = civec[loc[0]:loc[1]].reshape(nocca,nvira)
c1b = civec[loc[1]:loc[2]].reshape(noccb,nvirb)
c2ab = civec[loc[2]:loc[3]].reshape(nocca,noccb,nvira,nvirb)
c2aa = _unpack_4fold(civec[loc[3]:loc[4]], nocca, nvira)
c2bb = _unpack_4fold(civec[loc[4]:loc[5]], noccb, nvirb)
return c0, (c1a,c1b), (c2aa,c2ab,c2bb)
def from_fcivec(ci0, norb, nelec, frozen=0):
from pyscf.ci.gcisd import t2strs
if frozen is not 0:
raise NotImplementedError
if isinstance(nelec, (int, numpy.number)):
nelecb = nelec // 2
neleca = nelec - nelecb
else:
neleca, nelecb = nelec
norba = norbb = norb
nocc = nocca, noccb = neleca, nelecb
nvira = norba - nocca
nvirb = norbb - noccb
t1addra, t1signa = cisd.t1strs(norba, nocca)
t1addrb, t1signb = cisd.t1strs(norbb, noccb)
na = cistring.num_strings(norba, nocca)
nb = cistring.num_strings(norbb, noccb)
ci0 = ci0.reshape(na, nb)
c0 = ci0[0, 0]
c1a = ((ci0[t1addra, 0] * t1signa).reshape(nvira, nocca).T)[::-1]
c1b = ((ci0[0, t1addrb] * t1signb).reshape(nvirb, noccb).T)[::-1]
c2ab = numpy.einsum('i,j,ij->ij', t1signa, t1signb, ci0[t1addra][:,
t1addrb])
c2ab = c2ab.reshape(nvira, nocca, nvirb, noccb).transpose(1, 3, 0, 2)
c2ab = c2ab[::-1, ::-1]
t2addra, t2signa = t2strs(norba, nocca)
c2aa = (ci0[t2addra, 0] * t2signa).reshape(nvira * (nvira - 1) // 2, -1).T
c2aa = _unpack_4fold(c2aa[::-1], nocca, nvira)
t2addrb, t2signb = t2strs(norbb, noccb)
c2bb = (ci0[0, t2addrb] * t2signb).reshape(nvirb * (nvirb - 1) // 2, -1).T
c2bb = _unpack_4fold(c2bb[::-1], noccb, nvirb)
return amplitudes_to_cisdvec(c0, (c1a, c1b), (c2aa, c2ab, c2bb))
def cisdvec_to_amplitudes(civec, nmo, nocc):
nvir = nmo - nocc
c0 = civec[0]
c1 = civec[1:nocc*nvir+1].reshape(nocc,nvir)
c2 = ccsd._unpack_4fold(civec[nocc*nvir+1:], nocc, nvir)
return c0, c1, c2
def cisdvec_to_amplitudes(civec, nmo, nocc):
nvir = nmo - nocc
c0 = civec[0]
c1 = civec[1:nocc*nvir+1].reshape(nocc,nvir)
c2 = ccsd._unpack_4fold(civec[nocc*nvir+1:], nocc, nvir)
return c0, c1, c2
