def test_kmp2_contract_eri_dm(self):
kmp2 = mp.KMP2(kmf)
kmp2.kernel()
e_tot = kmp2.e_tot
mo_coeff = kmf.mo_coeff
hcore = kmf.get_hcore()
for k in range(nkpts):
hcore[k] = reduce(np.dot, (mo_coeff[k].T.conj(), hcore[k], mo_coeff[k]))
dm1 = kmp2.make_rdm1()
dm2 = kmp2.make_rdm2()
e = 0
for k in range(nkpts):
e += np.einsum('pq,qp', dm1[k], hcore[k]).real / nkpts
ao2mo = kmp2._scf.with_df.ao2mo
idx = 0
for kp in range(nkpts):
for kq in range(nkpts):
for kr in range(nkpts):
ks = kmp2.khelper.kconserv[kp,kq,kr]
mop = mo_coeff[kp]
moq = mo_coeff[kq]
mor = mo_coeff[kr]
mos = mo_coeff[ks]
eri = ao2mo((mop,moq,mor,mos),
(kpts[kp], kpts[kq], kpts[kr], kpts[ks]),
compact=False).reshape(mop.shape[-1],moq.shape[-1],
mor.shape[-1],mos.shape[-1]) / nkpts
e += np.einsum('pqrs,pqrs',dm2[idx], eri).real * 0.5 / nkpts
idx += 1
e += cell.energy_nuc()
self.assertAlmostEqual(e, e_tot, 9)
scf.kghf.KGHF.MP2 = None
scf.krohf.KROHF.MP2 = None
if __name__ == '__main__':
from pyscf.pbc import gto, scf, mp
cell = gto.Cell()
cell.atom='''
C 0.000000000000 0.000000000000 0.000000000000
C 1.685068664391 1.685068664391 1.685068664391
'''
cell.basis = 'gth-szv'
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()
# Running HF and MP2 with 1x1x2 Monkhorst-Pack k-point mesh
kmf = scf.KRHF(cell, kpts=cell.make_kpts([1,1,2]), exxdiv=None)
ehf = kmf.kernel()
mymp = mp.KMP2(kmf)
emp2, t2 = mymp.kernel()
print(emp2 - -0.204721432828996)
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()
#
# KHF and KMP2 with 2x2x2 k-points
#
kpts = cell.make_kpts([2, 2, 2])
kmf = scf.KRHF(cell)
kmf.kpts = kpts
ehf = kmf.kernel()
mypt = mp.KMP2(kmf)
mypt.kernel()
print("KMP2 energy (per unit cell) =", mypt.e_tot)
#
# The KHF and KMP2 for single k-point calculation.
#
kpts = cell.get_abs_kpts([0.25, 0.25, 0.25])
kmf = scf.KRHF(cell)
kmf.kpts = kpts
ehf = kmf.kernel()
mypt = mp.KMP2(kmf)
mypt.kernel()
print("KMP2 energy (per unit cell) =", mypt.e_tot)
# suitable for most cases. The user can nonetheless tests the effect of using
# different values of 'omega'. The few lines below do this and verify that the
# results (in terms of both the HF and the MP2 energies) are not affected.
# In the output file, you can also
# grep -a "CPU time for j3c" [output_file]
# to see how the DF initialization time is affected by using different omega.
#
omegas = np.array([0.3, 0.5, 0.7, 0.9])
escfs = np.zeros_like(omegas)
emp2s = np.zeros_like(omegas)
for i, omega in enumerate(omegas):
mf = scf.KRHF(cell, kpts).rs_density_fit()
mf.with_df.omega = omega
mf.kernel()
escfs[i] = mf.e_tot
mmp = mp.KMP2(mf)
mmp.with_t2 = False
mmp.kernel()
emp2s[i] = mmp.e_corr
for omega, escf, emp2 in zip(omegas, escfs, emp2s):
print("%.2f %.10f %.10f" % (omega, escf, emp2))
maxdiffescf = escfs.max() - escfs.min()
maxdiffemp2 = emp2s.max() - emp2s.min()
print("Maximum difference in SCF energy: %.10f" % (maxdiffescf))
print("Maximum difference in MP2 energy: %.10f" % (maxdiffemp2))
''' example output:
0.30 -75.3226526450 -0.2242441141
0.50 -75.3226526440 -0.2242441145
0.70 -75.3226526451 -0.2242441148
0.90 -75.3226526455 -0.2242441143
Maximum difference in SCF energy: 0.0000000015