a = scf.UHF(mol)
ehf = a.scf()
####### This can be removed ######
frozen = [[0], [0]] # 1sa and 1sb
mcc = cc.UCCSD(a)
mcc.frozen = frozen
mcc.diis_space = 10
mcc.conv_tol = 1e-6
mcc.conv_tol_normt = 1e-6
mcc.max_cycle = 150
ecc = mcc.kernel()[0]
eris = mcc.ao2mo()
e3 = uccsd_t.kernel(mcc, eris, mcc.t1, mcc.t2)
lib.logger.info(mcc, "* CCSD(T) energy : %12.6f" % (ehf + ecc + e3))
l1, l2 = uccsd_t_lambda.kernel(mcc, eris, mcc.t1, mcc.t2)[1:]
rdm1a, rdm1b = uccsd_t_rdm.make_rdm1(mcc, mcc.t1, mcc.t2, l1, l2, eris=eris)
rdm2aa, rdm2ab, rdm2bb = uccsd_t_rdm.make_rdm2(mcc,
mcc.t1,
mcc.t2,
l1,
l2,
eris=eris)
mo_a = a.mo_coeff[0]
mo_b = a.mo_coeff[1]
nmoa = mo_a.shape[1]
nmob = mo_b.shape[1]
eriaa = ao2mo.kernel(a._eri, mo_a, compact=False).reshape([nmoa] * 4)
eribb = ao2mo.kernel(a._eri, mo_b, compact=False).reshape([nmob] * 4)
[1, (0., 0.757, -0.587)]],
basis='631g',
spin=2,
)
mf = scf.UHF(mol)
mf.conv_tol = 1e-14
ehf = mf.scf()
mycc = cc.UCCSD(mf)
mycc.conv_tol = 1e-10
mycc.conv_tol_normt = 1e-10
ecc, t1, t2 = mycc.kernel()
eris = mycc.ao2mo()
e3ref = uccsd_t.kernel(mycc, eris, t1, t2)
print(ehf + ecc + e3ref)
conv, l1, l2 = uccsd_t_lambda.kernel(mycc, eris, t1, t2)
g1 = kernel(mycc, t1, t2, l1, l2, eris=eris)
print(g1)
myccs = mycc.as_scanner()
mol.atom[0] = ["O", (0., 0., 0.001)]
mol.build(0, 0)
e1 = myccs(mol)
e1 += myccs.ccsd_t()
mol.atom[0] = ["O", (0., 0., -0.001)]
mol.build(0, 0)
e2 = myccs(mol)
e2 += myccs.ccsd_t()
print(g1[0, 2], (e1 - e2) / 0.002 * lib.param.BOHR)
#O 0. 0.0000000 -0.1480942
#H 0. 0.1122898 0.0740461
[1 , (0. , 0.757 ,-0.587)]],
basis = '631g',
spin=2,
)
mf = scf.UHF(mol)
mf.conv_tol = 1e-14
ehf = mf.scf()
mycc = cc.UCCSD(mf)
mycc.conv_tol = 1e-10
mycc.conv_tol_normt = 1e-10
ecc, t1, t2 = mycc.kernel()
eris = mycc.ao2mo()
e3ref = uccsd_t.kernel(mycc, eris, t1, t2)
print(ehf+ecc+e3ref)
conv, l1, l2 = uccsd_t_lambda.kernel(mycc, eris, t1, t2)
g1 = kernel(mycc, t1, t2, l1, l2, eris=eris)
print(g1)
myccs = mycc.as_scanner()
mol.atom[0] = ["O" , (0., 0., 0.001)]
mol.build(0, 0)
e1 = myccs(mol)
e1 += myccs.ccsd_t()
mol.atom[0] = ["O" , (0., 0.,-0.001)]
mol.build(0, 0)
e2 = myccs(mol)
e2 += myccs.ccsd_t()
print(g1[0,2], (e1-e2)/0.002*lib.param.BOHR)
#O 0. 0.0000000 -0.1480942
#H 0. 0.1122898 0.0740461