def test_dmd_high_cost(self):
cell = gto.Cell()
cell.atom = '''
C 0.000000000000 0.000000000000 0.000000000000
C 1.685068664391 1.685068664391 1.685068664391
'''
cell.basis = {'C': [[0, (0.8, 1.0)], [1, (1.0, 1.0)]]}
cell.pseudo = 'gth-pade'
cell.a = '''
0.000000000, 3.370137329, 3.370137329
3.370137329, 0.000000000, 3.370137329
3.370137329, 3.370137329, 0.000000000'''
cell.unit = 'B'
cell.verbose = 5
cell.build()
nmp = [1, 1, 2]
# treating 1*1*2 supercell at gamma point
supcell = super_cell(cell, nmp)
gmf = scf.GHF(supcell, exxdiv=None)
ehf = gmf.kernel()
gcc = cc.GCCSD(gmf)
gcc.conv_tol = 1e-12
gcc.conv_tol_normt = 1e-10
gcc.max_cycle = 250
ecc, t1, t2 = gcc.kernel()
print('GHF energy (supercell) %.7f \n' % (float(ehf) / 2.))
print('GCCSD correlation energy (supercell) %.7f \n' %
(float(ecc) / 2.))
eom = eom_gccsd.EOMIP(gcc)
e1, v = eom.ipccsd(nroots=2)
eom = eom_gccsd.EOMEA(gcc)
e2, v = eom.eaccsd(nroots=2, koopmans=True)
# Running HF and CCSD with 1x1x2 Monkhorst-Pack k-point mesh
kmf = scf.KGHF(cell, kpts=cell.make_kpts(nmp), exxdiv=None)
ehf2 = kmf.kernel()
mycc = cc.KGCCSD(kmf)
mycc.conv_tol = 1e-12
mycc.conv_tol_normt = 1e-10
mycc.max_cycle = 250
ecc2, t1, t2 = mycc.kernel()
print('GHF energy %.7f \n' % (float(ehf2)))
print('GCCSD correlation energy %.7f \n' % (float(ecc2)))
kptlist = cell.make_kpts(nmp)
eom = EOMIP(mycc)
e1_obt, v = eom.ipccsd(nroots=2, kptlist=[0])
eom = EOMEA(mycc)
e2_obt, v = eom.eaccsd(nroots=2, koopmans=True, kptlist=[0])
assert (ehf / 2 - ehf2 < 1e-10)
assert (ecc / 2 - ecc2 < 1e-10)
assert (e1[0] - (e1_obt[0][0]) < 1e-7)
assert (e2[0] - (e2_obt[0][0]) < 1e-7)
nmo = dm1a.shape[0]
eri_aa = mf.with_df.ao2mo(mf.mo_coeff[0], kpts=kpt).reshape([nmo]*4)
eri_bb = mf.with_df.ao2mo(mf.mo_coeff[1], kpts=kpt).reshape([nmo]*4)
eri_ab = mf.with_df.ao2mo((mf.mo_coeff[0],mf.mo_coeff[0],mf.mo_coeff[1],mf.mo_coeff[1]), kpts=kpt).reshape([nmo]*4)
hcore = mf.get_hcore()
h1a = reduce(numpy.dot, (mf.mo_coeff[0].conj().T, hcore, mf.mo_coeff[0]))
h1b = reduce(numpy.dot, (mf.mo_coeff[1].conj().T, hcore, mf.mo_coeff[1]))
e_tot = (numpy.einsum('ij,ji', h1a, dm1a) +
numpy.einsum('ij,ji', h1b, dm1b) +
numpy.einsum('ijkl,jilk', eri_aa, dm2aa)*.5 +
numpy.einsum('ijkl,jilk', eri_ab, dm2ab) +
numpy.einsum('ijkl,jilk', eri_bb, dm2bb)*.5 + mf.energy_nuc())
print("UCCSD energy based on CCSD density matrices =", e_tot.real)
mf = scf.addons.convert_to_ghf(mf)
mycc = cc.GCCSD(mf).run()
print("GCCSD energy (per unit cell) at k-point =", mycc.e_tot)
dm1 = mycc.make_rdm1()
dm2 = mycc.make_rdm2()
nao = cell.nao_nr()
nmo = mf.mo_coeff.shape[1]
mo = mf.mo_coeff[:nao] + mf.mo_coeff[nao:]
eri_mo = mf.with_df.ao2mo(mo, kpts=kpt).reshape([nmo]*4)
orbspin = mf.mo_coeff.orbspin
eri_mo[orbspin[:,None]!=orbspin] = 0
eri_mo[:,:,orbspin[:,None]!=orbspin] = 0
h1 = reduce(numpy.dot, (mf.mo_coeff.conj().T, mf.get_hcore(), mf.mo_coeff))
e_tot = numpy.einsum('ij,ji', h1, dm1) + numpy.einsum('ijkl,jilk', eri_mo, dm2)*.5 + mf.energy_nuc()
print("GCCSD energy based on CCSD density matrices =", e_tot.real)