def test_h2_spin_adapted_ab():
h2_file = os.path.join(DATA_DIRECTORY, "H2_sto-3g_singlet_0.7.hdf5")
molecule = MolecularData(filename=h2_file)
rdms = molecule.get_molecular_rdm(use_fci=True)
dim = molecule.n_qubits
paulis_to_measure = pauli_terms_for_tpdm(dim)
pauli_to_coeff = {}
for term in paulis_to_measure:
# convert back to FermionOperator
qubit_op = pyquilpauli_to_qubitop(term_with_coeff(term, 1.0))
pauli_to_coeff[term.id()] = rdms.expectation(qubit_op)
tpdm = pauli_to_tpdm(dim, pauli_to_coeff)
d2aa, d2bb, d2ab = get_sz_spin_adapted(tpdm)
paulis_to_measure_ab = pauli_terms_for_tpdm_ab(dim // 2)
pauli_to_coeff = {}
for term in paulis_to_measure_ab:
# convert back to FermionOperator
qubit_op = pyquilpauli_to_qubitop(term_with_coeff(term, 1.0))
pauli_to_coeff[term.id()] = rdms.expectation(qubit_op)
tpdm_ab = pauli_to_tpdm_ab(dim // 2, pauli_to_coeff)
assert np.allclose(d2ab, tpdm_ab)
def remove_imaginary_terms(pauli_sums: PauliSum) -> PauliSum:
"""
Remove the imaginary component of each term in a Pauli sum.
:param pauli_sums: The Pauli sum to process.
:return: a purely Hermitian Pauli sum.
"""
if not isinstance(pauli_sums, PauliSum):
raise TypeError("not a pauli sum. please give me one")
new_term = sI(0) * 0.0
for term in pauli_sums:
new_term += term_with_coeff(term, term.coefficient.real)
return new_term
def test_lih_tpdm_ab_build():
"""
Check if 2-RDM construction from pauli terms works for the ab block
"""
lih_file = os.path.join(DATA_DIRECTORY, "H1-Li1_sto-3g_singlet_1.45.hdf5")
molecule = MolecularData(filename=lih_file)
rdms = molecule.get_molecular_rdm(use_fci=True)
dim = molecule.n_qubits
d2aa, d2bb, d2ab = get_sz_spin_adapted(molecule.fci_two_rdm)
paulis_to_measure = pauli_terms_for_tpdm_ab(dim // 2)
pauli_to_coeff = {}
for term in paulis_to_measure:
# convert back to FermionOperator
qubit_op = pyquilpauli_to_qubitop(term_with_coeff(term, 1.0))
pauli_to_coeff[term.id()] = rdms.expectation(qubit_op)
tpdm_ab = pauli_to_tpdm_ab(dim // 2, pauli_to_coeff)
assert np.allclose(tpdm_ab, d2ab)
def test_h2_tpdm_build():
"""
Check if constructing the 2-RDM (full) works. This check uses openfermion
data and thus requires openfermion to be installed
"""
h2_file = os.path.join(DATA_DIRECTORY, "H2_sto-3g_singlet_0.7.hdf5")
molecule = MolecularData(filename=h2_file)
rdms = molecule.get_molecular_rdm(use_fci=True)
dim = molecule.n_qubits
paulis_to_measure = pauli_terms_for_tpdm(dim)
pauli_to_coeff = {}
for term in paulis_to_measure:
# convert back to FermionOperator
qubit_op = pyquilpauli_to_qubitop(term_with_coeff(term, 1.0))
pauli_to_coeff[term.id()] = rdms.expectation(qubit_op)
tpdm = pauli_to_tpdm(dim, pauli_to_coeff)
assert np.allclose(tpdm, molecule.fci_two_rdm)
def test_term_with_coeff():
assert PauliTerm('X', 0, 1.j) == term_with_coeff(sX(0), 1.j)
assert PauliTerm('X', 0, -1.0) == term_with_coeff(sX(0), -1)
with pytest.raises(ValueError):
term_with_coeff(sI(0), None)
def test_term_with_coeff():
q0 = QubitPlaceholder()
assert PauliTerm('X', q0, 1.j) == term_with_coeff(sX(q0), 1.j)
assert PauliTerm('X', q0, -1.0) == term_with_coeff(sX(q0), -1)
with pytest.raises(ValueError):
term_with_coeff(sI(q0), None)
