def get_solver(self, problem, qubit_converter):
particle_number = cast(
ParticleNumber,
problem.grouped_property_transformed.get_property(
ParticleNumber),
)
num_spin_orbitals = particle_number.num_spin_orbitals
num_particles = (particle_number.num_alpha,
particle_number.num_beta)
initial_state = HartreeFock(num_spin_orbitals, num_particles,
qubit_converter)
ansatz = UCC(
qubit_converter=qubit_converter,
num_particles=num_particles,
num_spin_orbitals=num_spin_orbitals,
excitations="d",
initial_state=initial_state,
)
vqe = VQE(
ansatz=ansatz,
quantum_instance=self.minimum_eigensolver.quantum_instance,
optimizer=L_BFGS_B(),
)
return vqe
def test_custom_excitations(self, num_spin_orbitals, num_particles, excitations):
"""Tests if an error is raised when the excitations have a wrong format"""
converter = QubitConverter(JordanWignerMapper())
# pylint: disable=unused-argument
def custom_excitations(num_spin_orbitals, num_particles):
return excitations
with self.assertRaises(QiskitNatureError):
ansatz = UCC(
qubit_converter=converter,
num_particles=num_particles,
num_spin_orbitals=num_spin_orbitals,
excitations=custom_excitations,
)
ansatz.excitation_ops()
def test_vqe_uccsd(self):
"""Test VQE UCCSD case"""
solver = VQEUCCFactory(
quantum_instance=QuantumInstance(BasicAer.get_backend("statevector_simulator")),
ansatz=UCC(excitations="d"),
)
calc = GroundStateEigensolver(self.qubit_converter, solver)
res = calc.solve(self.electronic_structure_problem)
self.assertAlmostEqual(res.total_energies[0], self.reference_energy, places=6)
def test_ucc_ansatz(self, excitations, num_spin_orbitals, num_particles,
expect):
"""Tests the UCC Ansatz."""
converter = QubitConverter(JordanWignerMapper())
ansatz = UCC(qubit_converter=converter,
num_particles=num_particles,
num_spin_orbitals=num_spin_orbitals,
excitations=excitations)
assert_ucc_like_ansatz(self, ansatz, num_spin_orbitals, expect)
def test_transpile_no_parameters(self):
"""Test transpilation without parameters"""
num_spin_orbitals = 8
num_particles = (2, 2)
qubit_converter = QubitConverter(mapper=JordanWignerMapper())
ansatz = UCC(
num_spin_orbitals=num_spin_orbitals,
num_particles=num_particles,
qubit_converter=qubit_converter,
excitations="s",
)
ansatz = transpile(ansatz, optimization_level=3)
self.assertEqual(ansatz.num_qubits, 8)
def get_solver(self, problem, qubit_converter):
q_molecule_transformed = cast(
QMolecule, problem.molecule_data_transformed)
num_molecular_orbitals = q_molecule_transformed.num_molecular_orbitals
num_particles = (q_molecule_transformed.num_alpha,
q_molecule_transformed.num_beta)
num_spin_orbitals = 2 * num_molecular_orbitals
initial_state = HartreeFock(num_spin_orbitals, num_particles,
qubit_converter)
ansatz = UCC(qubit_converter=qubit_converter,
num_particles=num_particles,
num_spin_orbitals=num_spin_orbitals,
excitations='d',
initial_state=initial_state)
vqe = VQE(ansatz=ansatz,
quantum_instance=self._quantum_instance,
optimizer=L_BFGS_B())
return vqe
def _build_qeom_hopping_ops(
particle_number: ParticleNumber,
qubit_converter: QubitConverter,
excitations: Union[str, int, List[int],
Callable[[int, Tuple[int, int]],
List[Tuple[Tuple[int, ...],
Tuple[int, ...]]]], ] = "sd",
) -> Tuple[Dict[str, PauliSumOp], Dict[str, List[bool]], Dict[str, Tuple[Tuple[
int, ...], Tuple[int, ...]]], ]:
"""Builds the product of raising and lowering operators (basic excitation operators)
Args:
particle_number: the `ParticleNumber` property containing relevant sector information.
qubit_converter: the `QubitConverter` to use for mapping and symmetry reduction. The Z2
symmetries stored in this instance are the basis for the commutativity
information returned by this method.
excitations: the types of excitations to consider. The simple cases for this input are:
- a `str` containing any of the following characters: `s`, `d`, `t` or `q`.
- a single, positive `int` denoting the excitation type (1 == `s`, etc.).
- a list of positive integers.
- and finally a callable which can be used to specify a custom list of excitations.
For more details on how to write such a function refer to the default method,
:meth:`generate_fermionic_excitations`.
Returns:
A tuple containing the hopping operators, the types of commutativities and the excitation
indices.
"""
num_alpha, num_beta = particle_number.num_alpha, particle_number.num_beta
num_spin_orbitals = particle_number.num_spin_orbitals
excitations_list: List[Tuple[Tuple[int, ...], Tuple[int, ...]]]
if isinstance(excitations,
(str, int)) or (isinstance(excitations, list) and all(
isinstance(exc, int) for exc in excitations)):
ansatz = UCC(qubit_converter, (num_alpha, num_beta), num_spin_orbitals,
excitations)
excitations_list = ansatz._get_excitation_list()
else:
excitations_list = cast(List[Tuple[Tuple[int, ...], Tuple[int, ...]]],
excitations)
size = len(excitations_list)
# build all hopping operators
hopping_operators: Dict[str, PauliSumOp] = {}
type_of_commutativities: Dict[str, List[bool]] = {}
excitation_indices: Dict[str, Tuple[Tuple[int, ...], Tuple[int, ...]]] = {}
to_be_executed_list = []
for idx in range(size):
to_be_executed_list += [
excitations_list[idx], excitations_list[idx][::-1]
]
hopping_operators[f"E_{idx}"] = None
hopping_operators[f"Edag_{idx}"] = None
type_of_commutativities[f"E_{idx}"] = None
type_of_commutativities[f"Edag_{idx}"] = None
excitation_indices[f"E_{idx}"] = excitations_list[idx]
excitation_indices[f"Edag_{idx}"] = excitations_list[idx][::-1]
result = parallel_map(
_build_single_hopping_operator,
to_be_executed_list,
task_args=(num_spin_orbitals, qubit_converter),
num_processes=algorithm_globals.num_processes,
)
for key, res in zip(hopping_operators.keys(), result):
hopping_operators[key] = res[0]
type_of_commutativities[key] = res[1]
return hopping_operators, type_of_commutativities, excitation_indices
def test_build_ucc(self):
"""Test building UCC"""
ucc = UCC()
with self.subTest("Check defaulted construction"):
self.assertIsNone(ucc.num_particles)
self.assertIsNone(ucc.num_spin_orbitals)
self.assertIsNone(ucc.excitations)
self.assertIsNone(ucc.qubit_converter)
self.assertIsNone(ucc.operators)
self.assertEqual(ucc.num_qubits, 0)
with self.assertRaises(ValueError):
_ = ucc.data
with self.subTest("Set num particles"):
ucc.num_particles = (1, 1)
self.assertEqual(ucc.num_particles, (1, 1))
self.assertIsNone(ucc.operators)
with self.assertRaises(ValueError):
_ = ucc.data
with self.subTest("Set num spin orbitals"):
ucc.num_spin_orbitals = 4
self.assertEqual(ucc.num_spin_orbitals, 4)
self.assertIsNone(ucc.operators)
with self.assertRaises(ValueError):
_ = ucc.data
with self.subTest("Set excitations"):
ucc.excitations = "sd"
self.assertEqual(ucc.excitations, "sd")
self.assertIsNone(ucc.operators)
with self.assertRaises(ValueError):
_ = ucc.data
with self.subTest("Set qubit converter to complete build"):
converter = QubitConverter(JordanWignerMapper())
ucc.qubit_converter = converter
self.assertEqual(ucc.qubit_converter, converter)
self.assertIsNotNone(ucc.operators)
self.assertEqual(len(ucc.operators), 3)
self.assertEqual(ucc.num_qubits, 4)
self.assertIsNotNone(ucc.data)
with self.subTest("Set custom operators"):
self.assertEqual(len(ucc.operators), 3)
ucc.operators = ucc.operators[:2]
self.assertEqual(len(ucc.operators), 2)
self.assertEqual(ucc.num_qubits, 4)
with self.subTest("Reset operators back to as per UCC"):
ucc.operators = None
self.assertEqual(ucc.num_qubits, 4)
self.assertIsNotNone(ucc.operators)
self.assertEqual(len(ucc.operators), 3)
with self.subTest("Set num particles to include 0"):
ucc.num_particles = (1, 0)
self.assertEqual(ucc.num_particles, (1, 0))
self.assertIsNotNone(ucc.operators)
self.assertEqual(len(ucc.operators), 1)
with self.subTest("Change num particles"):
ucc.num_particles = (1, 1)
self.assertIsNotNone(ucc.operators)
self.assertEqual(len(ucc.operators), 3)
with self.subTest("Change num spin orbitals"):
ucc.num_spin_orbitals = 6
self.assertIsNotNone(ucc.operators)
self.assertEqual(len(ucc.operators), 8)
with self.subTest("Change excitations"):
ucc.excitations = "s"
self.assertIsNotNone(ucc.operators)
self.assertEqual(len(ucc.operators), 4)
with self.subTest("Change qubit converter"):
ucc.qubit_converter = QubitConverter(ParityMapper(),
two_qubit_reduction=True)
# Has not been used to convert so we need to force it to do two qubit reduction
ucc.qubit_converter.force_match(ucc.num_particles)
self.assertIsNotNone(ucc.operators)
self.assertEqual(ucc.num_qubits, 4)