def test_DFCASCI_natorb(self):
#
mol = gto.M(atom="C 0 0 0; C 0 0 1;", basis="ccpvdz", spin=2, verbose=0)
mf = scf.RHF(mol).density_fit().run()
ncas, nelecas = (8, 12)
mc = mcscf.CASCI(mf, ncas, nelecas).density_fit()
mc.fcisolver = shci.SHCI(mf.mol)
mc.natorb = True
mc.kernel()
mc.make_rdm1()
no_coeff = mc.mo_coeff
dm1_no = reduce(
numpy.dot,
(no_coeff.conj().T, mf.get_ovlp(), mc.make_rdm1(), mf.get_ovlp(), no_coeff),
)
numpy.testing.assert_allclose(
dm1_no.diagonal(), mc.mo_occ, rtol=3e-4, atol=1e-5
)
def test_SHCI_CASCI(self):
"""
Compare SHCI-CASCI calculation to CASCI calculation.
"""
mf = make_o2()
# Number of orbital and electrons
ncas = 8
nelecas = 12
mc = mcscf.CASCI(mf, ncas, nelecas)
e_casscf = mc.kernel()[0]
mc = mcscf.CASCI(mf, ncas, nelecas)
mc.fcisolver = shci.SHCI(mf.mol)
mc.fcisolver.stochastic = True
mc.fcisolver.nPTiter = 0 # Turn off perturbative calc.
mc.fcisolver.sweep_iter = [0]
mc.fcisolver.sweep_epsilon = [1e-12]
e_shciscf = mc.kernel()[0]
self.assertAlmostEqual(e_shciscf, e_casscf, places=6)
mc.fcisolver.cleanup_dice_files()
import os
from pyscf import gto, scf, ao2mo, mcscf, tools, fci
from pyscf.shciscf import shci, settings
alpha = 0.007297351
mol = gto.M(atom='C 0 0 0; C 0 0 1.3119',
basis='cc-pvqz',
verbose=5,
symmetry=1,
spin=2)
myhf = scf.RHF(mol)
myhf.kernel()
##USE SHCISCF
solver1 = shci.SHCI(mol)
solver1.irrep_nelec = {
'A1g': (2, 1),
'A1u': (1, 1),
'E1ux': (1, 1),
'E1uy': (1, 0)
}
solver1.prefix = "solver1"
solver1.epsilon2 = 1.e-7
solver1.stochastic = False
solver2 = shci.SHCI(mol)
solver2.irrep_nelec = {
'A1g': (2, 1),
'A1u': (1, 1),
'E1ux': (1, 0),
mf = scf.RHF(mol).run()
ncas, nelecas = (8, 10)
mc = mcscf.CASSCF(mf, ncas, nelecas)
mc.fcisolver.conv_tol = 1e-14
mc.kernel(mc.mo_coeff)
dm1, dm2, dm3 = fci.rdm.make_dm123("FCI3pdm_kern_sf", mc.ci, mc.ci, ncas,
nelecas)
dm1, dm2, dm3 = fci.rdm.reorder_dm123(dm1, dm2, dm3)
np.save("pyscf_1RDM.npy", dm1)
np.save("pyscf_2RDM.npy", dm2)
np.save("pyscf_3RDM.npy", dm3)
#
# Use orbitals for an approx. CASCI and create RDMs
#
mc2 = mcscf.CASCI(mf, ncas, nelecas)
mc2.fcisolver = shci.SHCI(mol)
mc2.fcisolver.sweep_iter = [0]
mc2.fcisolver.sweep_epsilon = [1e-10]
mc2.fcisolver.scratchDirectory = "."
mc2.kernel(mc.mo_coeff)
#
# Helpful Outputs
#
print(mc.ci.shape)
print(dm2.shape)
print(np.einsum("ii", dm1))
print(np.einsum("ii", np.einsum("ikjj", dm2) / (nelecas - 1)))