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)