def test_observable(me_table, init_term, mapping, terms_exp, monkeypatch):
r"""Tests the correctness of the 'observable' function used to build many-body observables.
The parametrized inputs `terms_exp` are `.terms` attribute of the corresponding
`QubitOperator. The equality checking is implemented in the `qchem` module itself
as it could be something useful to the users as well.
"""
res_obs = qchem.observable(me_table, init_term=init_term, mapping=mapping)
qubit_op = QubitOperator()
monkeypatch.setattr(qubit_op, "terms", terms_exp)
assert qchem._qubit_operators_equivalent(qubit_op, res_obs)
def test_spin_z(orbitals, mapping, terms_exp, monkeypatch):
r"""Tests the correctness of the :math:`\hat{S}_z` observable built by the
function `'spin_z'`.
The parametrized inputs are `.terms` attribute of the `QubitOperator. The equality
checking is implemented in the `qchem` module itself as it could be something
useful to the users as well.
"""
Sz = qchem.spin_z(orbitals, mapping=mapping)
Sz_qubit_op = QubitOperator()
monkeypatch.setattr(Sz_qubit_op, "terms", terms_exp)
assert qchem._qubit_operators_equivalent(Sz_qubit_op, Sz)
def test_particle_number_observable(n_orbitals, mapping, terms_exp, monkeypatch):
r"""Tests the correctness of the particle number observable :math:`\hat{N}` generated
by the ``'particle_number'`` function.
The parametrized inputs are `.terms` attribute of the particle number `QubitOperator`.
The equality checking is implemented in the `qchem` module itself as it could be
something useful to the users as well.
"""
N = qchem.particle_number(n_orbitals, mapping=mapping)
particle_number_qubit_op = QubitOperator()
monkeypatch.setattr(particle_number_qubit_op, "terms", terms_exp)
assert qchem._qubit_operators_equivalent(particle_number_qubit_op, N)
def test_hamiltonian_conversion(mol_name, terms_ref, monkeypatch):
r"""Test the correctness of the QubitOperator Hamiltonian conversion from
OpenFermion to Pennylane.
The parametrized inputs are `.terms` attribute of the output `QubitOperator`s based on
the same set of test molecules as `test_gen_hamiltonian_pauli_basis`.
The equality checking is implemented in the `qchem` module itself as it could be
something useful to the users as well.
"""
qOp = QubitOperator()
if terms_ref is not None:
monkeypatch.setattr(qOp, "terms", terms_ref)
vqe_hamiltonian = qchem.convert_hamiltonian(qOp)
assert qchem._qubit_operators_equivalent(qOp, vqe_hamiltonian)
def test_build_s2_observable(mol_name, n_act_elect, n_act_orb, mapping, terms_exp, monkeypatch):
r"""Tests the correctness of the built total-spin observable.
The parametrized inputs are `.terms` attribute of the total spin `QubitOperator.
The equality checking is implemented in the `qchem` module itself as it could be
something useful to the users as well.
"""
s2_me_table, init_term = qchem.get_spin2_matrix_elements(
mol_name, ref_dir, n_active_electrons=n_act_elect, n_active_orbitals=n_act_orb
)
s2_obs = qchem.observable(s2_me_table, init_term=init_term, mapping=mapping)
s2_qubit_op = QubitOperator()
monkeypatch.setattr(s2_qubit_op, "terms", terms_exp)
assert qchem._qubit_operators_equivalent(s2_qubit_op, s2_obs)
def test_observable_conversion(mol_name, terms_ref, custom_wires, monkeypatch):
r"""Test the correctness of the QubitOperator observable conversion from
OpenFermion to Pennylane.
The parametrized inputs are `.terms` attribute of the output `QubitOperator`s based on
the same set of test molecules as `test_gen_hamiltonian_pauli_basis`.
The equality checking is implemented in the `qchem` module itself as it could be
something useful to the users as well.
"""
qOp = QubitOperator()
if terms_ref is not None:
monkeypatch.setattr(qOp, "terms", terms_ref)
vqe_observable = qchem.convert_observable(qOp, custom_wires)
if isinstance(custom_wires, dict):
custom_wires = {v: k for k, v in custom_wires.items()}
assert qchem._qubit_operators_equivalent(qOp, vqe_observable, custom_wires)
