def test_rdms_psi4():
rdm1_ref = numpy.array([[1.97710662, 0.0], [0.0, 0.02289338]])
rdm2_ref = numpy.array([[[[1.97710662, 0.0], [0.0, -0.21275021]], [[0.0, 0.0], [0.0, 0.0]]],
[[[0.0, 0.0], [0.0, 0.0]], [[-0.21275021, 0.0], [0.0, 0.02289338]]]])
mol = qc.Molecule(geometry="data/h2.xyz", basis_set="sto-3g", backend="psi4", transformation="jw")
# Check matrices by psi4
mol.compute_rdms(U=None, psi4_method="detci", psi4_options={"detci__ex_level": 2,
"detci__opdm": True, "detci__tpdm": True})
rdm1, rdm2 = mol.rdm1, mol.rdm2
assert (numpy.allclose(rdm1, rdm1_ref, atol=1e-8))
assert (numpy.allclose(rdm2, rdm2_ref, atol=1e-8))
def test_rdms(trafo):
rdm1_ref = numpy.array([[1.99137832, -0.00532359],
[-0.00532359, 0.00862168]])
rdm2_ref = numpy.array([[[[1.99136197e+00, -5.69817110e-03],
[-5.69817110e-03, -1.30905760e-01]],
[[-5.69817110e-03, 1.63522163e-05],
[1.62577807e-05, 3.74579524e-04]]],
[[[-5.69817110e-03, 1.62577807e-05],
[1.63522163e-05, 3.74579524e-04]],
[[-1.30905760e-01, 3.74579524e-04],
[3.74579524e-04, 8.60532554e-03]]]])
def rdm_circuit(angles) -> tq.circuit.QCircuit:
# Handwritten circuit for Helium-atom in minimal basis
U = tq.gates.X(target=0)
U += tq.gates.X(target=1)
U += tq.gates.Ry(target=3, control=0, angle=-1 / 2 * angles[0])
U += tq.gates.X(target=0)
U += tq.gates.X(target=1, control=3)
U += tq.gates.Ry(target=2, control=1, angle=-1 / 2 * angles[1])
U += tq.gates.X(target=1)
U += tq.gates.Ry(target=2, control=1, angle=-1 / 2 * angles[2])
U += tq.gates.X(target=1)
U += tq.gates.X(target=2)
U += tq.gates.X(target=0, control=2)
U += tq.gates.X(target=2)
return U
mol = qc.Molecule(geometry="data/he.xyz",
basis_set="6-31g",
transformation=trafo)
# Random angles - check consistency of spin-free, spin-ful matrices
ang = numpy.random.uniform(low=0, high=1, size=3)
U_random = rdm_circuit(angles=ang)
# Spin-free matrices
mol.compute_rdms(U=U_random, spin_free=True)
rdm1_sfree, rdm2_sfree = mol.rdm1, mol.rdm2
# Spin-orbital matrices
mol.compute_rdms(U=U_random, spin_free=False)
rdm1_spinsum, rdm2_spinsum = mol.rdm_spinsum(sum_rdm1=True, sum_rdm2=True)
assert (numpy.allclose(rdm1_sfree, rdm1_spinsum, atol=1e-8))
assert (numpy.allclose(rdm2_sfree, rdm2_spinsum, atol=1e-8))
# Fixed angles - check consistency of result
ang = [-0.26284376686921973, -0.010829810670240182, 6.466541685258823]
U_fixed = rdm_circuit(angles=ang)
mol.compute_rdms(U=U_fixed, spin_free=True)
rdm1_sfree, rdm2_sfree = mol.rdm1, mol.rdm2
assert (numpy.allclose(rdm1_sfree, rdm1_ref, atol=1e-8))
assert (numpy.allclose(rdm2_sfree, rdm2_ref, atol=1e-8))
def obtain_PES(molecule, bond_lengths, basis, method, print_log=True):
if method.lower() not in ['ccsd', 'cisd', 'fci', 'hf']:
raise (ValueError(
"Method not recognized, implemented methods are 'ccsd', 'cisd', 'fci', 'hf'."
))
gridpoints = len(bond_lengths)
energies = np.zeros(gridpoints)
for i in range(gridpoints):
obtained_e = False
nudged_geo_tries = 0
while obtained_e == False:
try:
mol_data = get_molecular_data(molecule,
bond_lengths[i],
xyz_format=True)
mol_data = quantumchemistry.Molecule(mol_data, basis)
if method == 'cisd':
result = mol_data.compute_energy(
'detci', options={"detci__ex_level": 2})
else:
result = mol_data.compute_energy(method)
if print_log:
print("E = {} Eh".format(result))
energies[i] = result
obtained_e = True
except:
#Nudge geometry, cross fingers
bond_lengths[i] += 0.00000042
nudged_geo_tries += 1
if nudged_geo_tries > 9:
obtained_e = True
energies[i] = np.nan
print("Could not converge")
return energies