def test_default(self):
""" Default execution """
solver = VQEUCCSDFactory(
QuantumInstance(BasicAer.get_backend('statevector_simulator')))
calc = AdaptVQE(self.transformation, solver)
res = calc.solve(self.driver)
self.assertAlmostEqual(res.electronic_energy, self.expected, places=6)
def test_custom_minimum_eigensolver(self):
""" Test custom MES """
# Note: the VQEUCCSDFactory actually allows to specify an optimizer through its constructor.
# Thus, this example is quite far fetched but for a proof-of-principle test it still works.
class CustomFactory(VQEUCCSDFactory):
"""A custom MESFactory"""
def get_solver(self, transformation):
num_orbitals = transformation.molecule_info['num_orbitals']
num_particles = transformation.molecule_info['num_particles']
qubit_mapping = transformation.qubit_mapping
two_qubit_reduction = transformation.molecule_info[
'two_qubit_reduction']
z2_symmetries = transformation.molecule_info['z2_symmetries']
initial_state = HartreeFock(num_orbitals, num_particles,
qubit_mapping, two_qubit_reduction,
z2_symmetries.sq_list)
var_form = UCCSD(num_orbitals=num_orbitals,
num_particles=num_particles,
initial_state=initial_state,
qubit_mapping=qubit_mapping,
two_qubit_reduction=two_qubit_reduction,
z2_symmetries=z2_symmetries)
vqe = VQE(var_form=var_form,
quantum_instance=self._quantum_instance,
optimizer=L_BFGS_B())
return vqe
solver = CustomFactory(
QuantumInstance(BasicAer.get_backend('statevector_simulator')))
calc = AdaptVQE(self.transformation, solver)
res = calc.solve(self.driver)
self.assertAlmostEqual(res.electronic_energy, self.expected, places=6)
def test_aux_ops_reusability(self):
""" Test that the auxiliary operators can be reused """
# Regression test against #1475
solver = VQEUCCSDFactory(QuantumInstance(BasicAer.get_backend('statevector_simulator')))
calc = AdaptVQE(self.transformation, solver)
modes = 4
h_1 = np.eye(modes, dtype=complex)
h_2 = np.zeros((modes, modes, modes, modes))
aux_ops = [FermionicOperator(h_1, h_2)]
aux_ops_copy = copy.deepcopy(aux_ops)
_ = calc.solve(self.driver, aux_ops)
assert all([a == b for a, b in zip(aux_ops, aux_ops_copy)])
def test_custom_excitation_pool(self):
""" Test custom excitation pool """
class CustomFactory(VQEUCCSDFactory):
"""A custom MES factory."""
def get_solver(self, transformation):
solver = super().get_solver(transformation)
# Here, we can create essentially any custom excitation pool.
# For testing purposes only, we simply select some hopping operator already
# available in the variational form object.
# pylint: disable=no-member
custom_excitation_pool = [solver.var_form._hopping_ops[2]]
solver.var_form.excitation_pool = custom_excitation_pool
return solver
solver = CustomFactory(
QuantumInstance(BasicAer.get_backend('statevector_simulator')))
calc = AdaptVQE(self.transformation, solver)
res = calc.solve(self.driver)
self.assertAlmostEqual(res.electronic_energy, self.expected, places=6)