def run_hci_pyscf(h,
g,
nelec,
ecore=0,
select_cutoff=5e-4,
ci_cutoff=5e-4,
nroots=1):
# {{{
#heat bath ci
from pyscf import mcscf
from pyscf.hci import hci
cisolver = hci.SCI()
cisolver.select_cutoff = select_cutoff
cisolver.ci_coeff_cutoff = ci_cutoff
ehci, civec = cisolver.kernel(h,
g,
h.shape[1],
nelec,
ecore=ecore,
verbose=4,
nroots=nroots)
hci_dim = civec[0].shape[0]
print(" HCI: %12.8f Dim:%6d" % (ehci, hci_dim))
print("HCI %10.8f" % (ehci))
#for i in range(0,nroots):
# print("HCI %10.8f"%(ehci[i]))
#hci_dim = 1
return ehci, hci_dim
do_hci = 1
if do_fci:
# FCI
from pyscf import fci
cisolver = fci.direct_spin1.FCI(mol)
efci, ci = cisolver.kernel(h, g, h.shape[1], mol.nelectron, ecore=0)
fci_dim = ci.shape[0] * ci.shape[1]
print(" FCI: %12.8f Dim:%6d" % (efci, fci_dim))
print("FCI %10.8f" % (efci + enu))
if do_hci:
#heat bath ci
from pyscf import mcscf
from pyscf.hci import hci
cisolver = hci.SCI(mol)
ehci, civec = cisolver.kernel(h,
g,
h.shape[1],
mol.nelectron,
ecore=0,
verbose=4)
hci_dim = civec[0].shape[0]
print(" HCI: %12.8f Dim:%6d" % (ehci, hci_dim))
print("HCI %10.8f" % (ehci + enu))
blocks = [[0, 1, 2], [3, 4, 5]]
#blocks = [[0,1],[2,3],[4,5],[6,7]]
n_blocks = len(blocks)
clusters = []
def test_1():
n_cluster_states = 1000
from pyscf import gto, scf, mcscf, ao2mo
mol = gto.Mole()
mol.atom = '''
H 0.00 0.00 0.00
H 0.00 0.00 1.50
H 0.00 0.00 3.00
H 0.00 2.00 0.00
H 0.00 2.00 1.50
H 0.00 2.10 3.00
'''
mol.charge = +0
mol.spin = +0
mol.max_memory = 1000 # MB
mol.basis = 'sto-3g'
myhf = scf.RHF(mol).run()
print(myhf.mo_energy)
#exit()
n_orb = myhf.mo_coeff.shape[1]
nel,temp = mol.nelec
print(nel)
#g.shape = (n_orb,n_orb,n_orb,n_orb)
enu = myhf.energy_nuc()
S = mol.intor('int1e_ovlp_sph')
local = 'lowdin'
local = 'p'
if local == 'lowdin':
print("Using lowdin orthogonalized orbitals")
#forming S^-1/2 to transform to A and B block.
sal, svec = np.linalg.eigh(S)
idx = sal.argsort()[::-1]
sal = sal[idx]
svec = svec[:, idx]
sal = sal**-0.5
sal = np.diagflat(sal)
X = svec @ sal @ svec.T
C = cp.deepcopy(X)
h = C.T.dot(myhf.get_hcore()).dot(C)
g = ao2mo.kernel(mol,C,aosym='s4',compact=False).reshape(4*((n_orb),))
else:
h = myhf.mo_coeff.T.dot(myhf.get_hcore()).dot(myhf.mo_coeff)
g = ao2mo.kernel(mol,myhf.mo_coeff,aosym='s4',compact=False).reshape(4*((n_orb),))
print(g.shape)
do_fci = 1
do_hci = 1
if do_fci:
# FCI
from pyscf import fci
cisolver = fci.direct_spin1.FCI(mol)
efci, ci = cisolver.kernel(h, g, h.shape[1], mol.nelectron, ecore=0)
fci_dim = ci.shape[0]*ci.shape[1]
print(" FCI: %12.8f Dim:%6d"%(efci,fci_dim))
print("FCI %10.8f"%(efci+enu))
if do_hci:
#heat bath ci
from pyscf import mcscf
from pyscf.hci import hci
cisolver = hci.SCI(mol)
ehci, civec = cisolver.kernel(h, g, h.shape[1], mol.nelectron, ecore=0,verbose=4)
hci_dim = civec[0].shape[0]
print(" HCI: %12.8f Dim:%6d"%(ehci,hci_dim))
print("HCI %10.8f"%(ehci+enu))
blocks = [[0,1,2],[3,4,5]]
#blocks = [[0,1],[2,3],[4,5],[6,7]]
n_blocks = len(blocks)
ecore=0.0
init_fspace = ((3,3),(0,0))
clusters, clustered_ham, ci_vector, cmf_out = system_setup(h, g, ecore, blocks, init_fspace, cmf_maxiter = 0 )
ci_vector = ClusteredState()
ci_vector.init(clusters,((3,3),(0,0)))
ci_vector.add_fockspace(((2,2),(1,1)))
ci_vector.add_fockspace(((1,3),(2,0)))
ci_vector.add_fockspace(((3,1),(0,2)))
ci_vector.add_fockspace(((3,2),(0,1)))
ci_vector.add_fockspace(((2,3),(1,0)))
#ci_vector.init(((1,1),(1,1),(0,0),(0,0)))
#ci_vector.expand_to_full_space()
ci_vector.expand_each_fock_space(clusters)
e_prev = 0
thresh_conv = 1e-8
ci_vector_ref = ci_vector.copy()
e_last = 0
#ci_vector.print_configs()
ci_vector, pt_vector, e0, e2 = tp_cipsi(ci_vector_ref.copy(), clustered_ham, thresh_cipsi=1e-14, thresh_ci_clip=0, max_iter=0)
#print(ci_vector.get_vector())
#ci_vector.print_configs()
civec = ci_vector.get_vector()
occ = nel
vir = n_orb - occ
ci_ab = civec[1:nel*nel*nel*nel+1].reshape(occ*occ,vir*vir)
print(ci_ab)
U,s,Vt = np.linalg.svd(ci_ab)
print(s)
bcci_dim = len(ci_vector)
print("BCCI: %12.8f Dim:%6d"%(e0+enu,bcci_dim))
print(" HCI: %12.8f Dim:%6d"%(ehci+enu,hci_dim))
print(" FCI: %12.8f Dim:%6d"%(efci+enu,fci_dim))
from pyscf import ci
myci = ci.CISD(myhf).run()
assert(abs(myci.e_tot - e0-enu) < 1e-7)
assert(abs(myci.e_tot - e0-enu) < 1e-7)