def run(
self, qmolecule: QMolecule
) -> Tuple[WeightedPauliOperator, List[WeightedPauliOperator]]:
""" run method"""
logger.debug('Processing started...')
# Save these values for later combination with the quantum computation result
self._hf_energy = qmolecule.hf_energy
self._nuclear_repulsion_energy = qmolecule.nuclear_repulsion_energy
self._nuclear_dipole_moment = qmolecule.nuclear_dipole_moment
self._reverse_dipole_sign = qmolecule.reverse_dipole_sign
core_list = qmolecule.core_orbitals if self._freeze_core else []
reduce_list = self._orbital_reduction
if self._freeze_core:
logger.info(
"Freeze_core specified. Core orbitals to be frozen: %s",
core_list)
if reduce_list:
logger.info("Configured orbital reduction list: %s", reduce_list)
reduce_list = [
x + qmolecule.num_orbitals if x < 0 else x for x in reduce_list
]
freeze_list = []
remove_list = []
# Orbitals are specified by their index from 0 to n-1, where n is the number of orbitals the
# molecule has. The combined list of the core orbitals, when freeze_core is true, with any
# user supplied orbitals is what will be used. Negative numbers may be used to indicate the
# upper virtual orbitals, so -1 is the highest, then -2 etc. and these will
# be converted to the
# positive 0-based index for computation.
# In the combined list any orbitals that are occupied are added to a freeze list and an
# energy is stored from these orbitals to be added later.
# Unoccupied orbitals are just discarded.
# Because freeze and eliminate is done in separate steps,
# with freeze first, we have to re-base
# the indexes for elimination according to how many orbitals were removed when freezing.
#
orb_list = list(set(core_list + reduce_list))
num_alpha = qmolecule.num_alpha
num_beta = qmolecule.num_beta
new_num_alpha = num_alpha
new_num_beta = num_beta
if orb_list:
orbitals_list = np.array(orb_list)
orbitals_list = \
orbitals_list[(cast(np.ndarray, orbitals_list) >= 0) &
(orbitals_list < qmolecule.num_orbitals)]
freeze_list_alpha = [i for i in orbitals_list if i < num_alpha]
freeze_list_beta = [i for i in orbitals_list if i < num_beta]
freeze_list = np.append(
freeze_list_alpha,
[i + qmolecule.num_orbitals for i in freeze_list_beta])
remove_list_alpha = [i for i in orbitals_list if i >= num_alpha]
remove_list_beta = [i for i in orbitals_list if i >= num_beta]
rla_adjust = -len(freeze_list_alpha)
rlb_adjust = -len(freeze_list_alpha) - len(
freeze_list_beta) + qmolecule.num_orbitals
remove_list = np.append(
[i + rla_adjust for i in remove_list_alpha],
[i + rlb_adjust for i in remove_list_beta])
logger.info("Combined orbital reduction list: %s", orbitals_list)
logger.info(
" converting to spin orbital reduction list: %s",
np.append(np.array(orbitals_list),
np.array(orbitals_list) + qmolecule.num_orbitals))
logger.info(" => freezing spin orbitals: %s", freeze_list)
logger.info(
" => removing spin orbitals: %s (indexes accounting for freeze %s)",
np.append(remove_list_alpha,
np.array(remove_list_beta) + qmolecule.num_orbitals),
remove_list)
new_num_alpha -= len(freeze_list_alpha)
new_num_beta -= len(freeze_list_beta)
new_nel = [new_num_alpha, new_num_beta]
fer_op = FermionicOperator(h1=qmolecule.one_body_integrals,
h2=qmolecule.two_body_integrals)
fer_op, self._energy_shift, did_shift = \
Hamiltonian._try_reduce_fermionic_operator(fer_op, freeze_list, remove_list)
if did_shift:
logger.info("Frozen orbital energy shift: %s", self._energy_shift)
if self._transformation == TransformationType.PARTICLE_HOLE.value:
fer_op, ph_shift = fer_op.particle_hole_transformation(new_nel)
self._ph_energy_shift = -ph_shift
logger.info("Particle hole energy shift: %s",
self._ph_energy_shift)
logger.debug('Converting to qubit using %s mapping',
self._qubit_mapping)
qubit_op = Hamiltonian._map_fermionic_operator_to_qubit(
fer_op, self._qubit_mapping, new_nel, self._two_qubit_reduction)
qubit_op.name = 'Electronic Hamiltonian'
logger.debug(' num paulis: %s, num qubits: %s', len(qubit_op.paulis),
qubit_op.num_qubits)
aux_ops = []
def _add_aux_op(aux_op, name):
aux_qop = Hamiltonian._map_fermionic_operator_to_qubit(
aux_op, self._qubit_mapping, new_nel,
self._two_qubit_reduction)
aux_qop.name = name
aux_ops.append(aux_qop)
logger.debug(' num paulis: %s', aux_qop.paulis)
logger.debug('Creating aux op for Number of Particles')
_add_aux_op(fer_op.total_particle_number(), 'Number of Particles')
logger.debug('Creating aux op for S^2')
_add_aux_op(fer_op.total_angular_momentum(), 'S^2')
logger.debug('Creating aux op for Magnetization')
_add_aux_op(fer_op.total_magnetization(), 'Magnetization')
if qmolecule.has_dipole_integrals():
def _dipole_op(dipole_integrals, axis):
logger.debug('Creating aux op for dipole %s', axis)
fer_op_ = FermionicOperator(h1=dipole_integrals)
fer_op_, shift, did_shift_ = self._try_reduce_fermionic_operator(
fer_op_, freeze_list, remove_list)
if did_shift_:
logger.info("Frozen orbital %s dipole shift: %s", axis,
shift)
ph_shift_ = 0.0
if self._transformation == TransformationType.PARTICLE_HOLE.value:
fer_op_, ph_shift_ = fer_op_.particle_hole_transformation(
new_nel)
ph_shift_ = -ph_shift_
logger.info("Particle hole %s dipole shift: %s", axis,
ph_shift_)
qubit_op_ = self._map_fermionic_operator_to_qubit(
fer_op_, self._qubit_mapping, new_nel,
self._two_qubit_reduction)
qubit_op_.name = 'Dipole ' + axis
logger.debug(' num paulis: %s', len(qubit_op_.paulis))
return qubit_op_, shift, ph_shift_
op_dipole_x, self._x_dipole_shift, self._ph_x_dipole_shift = \
_dipole_op(qmolecule.x_dipole_integrals, 'x')
op_dipole_y, self._y_dipole_shift, self._ph_y_dipole_shift = \
_dipole_op(qmolecule.y_dipole_integrals, 'y')
op_dipole_z, self._z_dipole_shift, self._ph_z_dipole_shift = \
_dipole_op(qmolecule.z_dipole_integrals, 'z')
aux_ops.append(op_dipole_x)
aux_ops.append(op_dipole_y)
aux_ops.append(op_dipole_z)
logger.info('Molecule num electrons: %s, remaining for processing: %s',
[num_alpha, num_beta], new_nel)
nspinorbs = qmolecule.num_orbitals * 2
new_nspinorbs = nspinorbs - len(freeze_list) - len(remove_list)
logger.info(
'Molecule num spin orbitals: %s, remaining for processing: %s',
nspinorbs, new_nspinorbs)
self._add_molecule_info(self.INFO_NUM_PARTICLES,
(new_num_alpha, new_num_beta))
self._add_molecule_info(self.INFO_NUM_ORBITALS, new_nspinorbs)
self._add_molecule_info(
self.INFO_TWO_QUBIT_REDUCTION, self._two_qubit_reduction
if self._qubit_mapping == 'parity' else False)
z2symmetries = Z2Symmetries([], [], [], None)
if self._z2symmetry_reduction is not None:
logger.debug('Processing z2 symmetries')
qubit_op, aux_ops, z2symmetries = self._process_z2symmetry_reduction(
qubit_op, aux_ops)
self._add_molecule_info(self.INFO_Z2SYMMETRIES, z2symmetries)
logger.debug('Processing complete ready to run algorithm')
return qubit_op, aux_ops
def _do_transform(
self,
qmolecule: QMolecule,
aux_operators: Optional[List[FermionicOperator]] = None
) -> Tuple[WeightedPauliOperator, List[WeightedPauliOperator]]:
"""
Args:
qmolecule: qmolecule
aux_operators: Additional ``FermionicOperator``s to map to a qubit operator.
Returns:
(qubit operator, auxiliary operators)
"""
logger.debug('Processing started...')
# Save these values for later combination with the quantum computation result
self._hf_energy = qmolecule.hf_energy
self._nuclear_repulsion_energy = qmolecule.nuclear_repulsion_energy
self._nuclear_dipole_moment = qmolecule.nuclear_dipole_moment
self._reverse_dipole_sign = qmolecule.reverse_dipole_sign
core_list = qmolecule.core_orbitals if self._freeze_core else []
reduce_list = self._orbital_reduction
if self._freeze_core:
logger.info(
"Freeze_core specified. Core orbitals to be frozen: %s",
core_list)
if reduce_list:
logger.info("Configured orbital reduction list: %s", reduce_list)
reduce_list = [
x + qmolecule.num_orbitals if x < 0 else x for x in reduce_list
]
freeze_list = []
remove_list = []
# Orbitals are specified by their index from 0 to n-1, where n is the number of orbitals the
# molecule has. The combined list of the core orbitals, when freeze_core is true, with any
# user supplied orbitals is what will be used. Negative numbers may be used to indicate the
# upper virtual orbitals, so -1 is the highest, then -2 etc. and these will
# be converted to the
# positive 0-based index for computation.
# In the combined list any orbitals that are occupied are added to a freeze list and an
# energy is stored from these orbitals to be added later.
# Unoccupied orbitals are just discarded.
# Because freeze and eliminate is done in separate steps,
# with freeze first, we have to re-base
# the indexes for elimination according to how many orbitals were removed when freezing.
#
orb_list = list(set(core_list + reduce_list))
num_alpha = qmolecule.num_alpha
num_beta = qmolecule.num_beta
new_num_alpha = num_alpha
new_num_beta = num_beta
if orb_list:
orbitals_list = np.array(orb_list)
orbitals_list = orbitals_list[
(cast(np.ndarray, orbitals_list) >= 0)
& (orbitals_list < qmolecule.num_orbitals)]
freeze_list_alpha = [i for i in orbitals_list if i < num_alpha]
freeze_list_beta = [i for i in orbitals_list if i < num_beta]
freeze_list = np.append(
freeze_list_alpha,
[i + qmolecule.num_orbitals for i in freeze_list_beta])
remove_list_alpha = [i for i in orbitals_list if i >= num_alpha]
remove_list_beta = [i for i in orbitals_list if i >= num_beta]
rla_adjust = -len(freeze_list_alpha)
rlb_adjust = -len(freeze_list_alpha) - len(
freeze_list_beta) + qmolecule.num_orbitals
remove_list = np.append(
[i + rla_adjust for i in remove_list_alpha],
[i + rlb_adjust for i in remove_list_beta])
logger.info("Combined orbital reduction list: %s", orbitals_list)
logger.info(
" converting to spin orbital reduction list: %s",
np.append(np.array(orbitals_list),
np.array(orbitals_list) + qmolecule.num_orbitals))
logger.info(" => freezing spin orbitals: %s", freeze_list)
logger.info(
" => removing spin orbitals: %s (indexes accounting for freeze %s)",
np.append(remove_list_alpha,
np.array(remove_list_beta) + qmolecule.num_orbitals),
remove_list)
new_num_alpha -= len(freeze_list_alpha)
new_num_beta -= len(freeze_list_beta)
new_nel = [new_num_alpha, new_num_beta]
# construct the fermionic operator
fer_op = FermionicOperator(h1=qmolecule.one_body_integrals,
h2=qmolecule.two_body_integrals)
# try to reduce it according to the freeze and remove list
fer_op, self._energy_shift, did_shift = \
FermionicTransformation._try_reduce_fermionic_operator(fer_op, freeze_list, remove_list)
# apply same transformation for the aux operators
if aux_operators is not None:
aux_operators = [
FermionicTransformation._try_reduce_fermionic_operator(
op, freeze_list, remove_list)[0] for op in aux_operators
]
if did_shift:
logger.info("Frozen orbital energy shift: %s", self._energy_shift)
# apply particle hole transformation, if specified
if self._transformation == FermionicTransformationType.PARTICLE_HOLE.value:
fer_op, ph_shift = fer_op.particle_hole_transformation(new_nel)
self._ph_energy_shift = -ph_shift
logger.info("Particle hole energy shift: %s",
self._ph_energy_shift)
# apply the same transformation for the aux operators
if aux_operators is not None:
aux_operators = [
op.particle_hole_transformation(new_nel)[0]
for op in aux_operators
]
logger.debug('Converting to qubit using %s mapping',
self._qubit_mapping)
qubit_op = FermionicTransformation._map_fermionic_operator_to_qubit(
fer_op, self._qubit_mapping, new_nel, self._two_qubit_reduction)
qubit_op.name = 'Fermionic Operator'
logger.debug(' num paulis: %s, num qubits: %s', len(qubit_op.paulis),
qubit_op.num_qubits)
aux_ops = [] # list of the aux operators
def _add_aux_op(aux_op: FermionicOperator, name: str) -> None:
"""
Add auxiliary operators
Args:
aux_op: auxiliary operators
name: name
"""
aux_qop = FermionicTransformation._map_fermionic_operator_to_qubit(
aux_op, self._qubit_mapping, new_nel,
self._two_qubit_reduction)
aux_qop.name = name
aux_ops.append(aux_qop)
logger.debug(' num paulis: %s', aux_qop.paulis)
# the first three operators are hardcoded to number of particles, angular momentum
# and magnetization in this order
logger.debug('Creating aux op for Number of Particles')
_add_aux_op(fer_op.total_particle_number(), 'Number of Particles')
logger.debug('Creating aux op for S^2')
_add_aux_op(fer_op.total_angular_momentum(), 'S^2')
logger.debug('Creating aux op for Magnetization')
_add_aux_op(fer_op.total_magnetization(), 'Magnetization')
# the next three are dipole moments, if supported by the qmolecule
if qmolecule.has_dipole_integrals():
self._has_dipole_moments = True
def _dipole_op(dipole_integrals: np.ndarray, axis: str) \
-> Tuple[WeightedPauliOperator, float, float]:
"""
Dipole operators
Args:
dipole_integrals: dipole integrals
axis: axis for dipole moment calculation
Returns:
(qubit_op_, shift, ph_shift_)
"""
logger.debug('Creating aux op for dipole %s', axis)
fer_op_ = FermionicOperator(h1=dipole_integrals)
fer_op_, shift, did_shift_ = self._try_reduce_fermionic_operator(
fer_op_, freeze_list, remove_list)
if did_shift_:
logger.info("Frozen orbital %s dipole shift: %s", axis,
shift)
ph_shift_ = 0.0
if self._transformation == FermionicTransformationType.PARTICLE_HOLE.value:
fer_op_, ph_shift_ = fer_op_.particle_hole_transformation(
new_nel)
ph_shift_ = -ph_shift_
logger.info("Particle hole %s dipole shift: %s", axis,
ph_shift_)
qubit_op_ = self._map_fermionic_operator_to_qubit(
fer_op_, self._qubit_mapping, new_nel,
self._two_qubit_reduction)
qubit_op_.name = 'Dipole ' + axis
logger.debug(' num paulis: %s', len(qubit_op_.paulis))
return qubit_op_, shift, ph_shift_
op_dipole_x, self._x_dipole_shift, self._ph_x_dipole_shift = \
_dipole_op(qmolecule.x_dipole_integrals, 'x')
op_dipole_y, self._y_dipole_shift, self._ph_y_dipole_shift = \
_dipole_op(qmolecule.y_dipole_integrals, 'y')
op_dipole_z, self._z_dipole_shift, self._ph_z_dipole_shift = \
_dipole_op(qmolecule.z_dipole_integrals, 'z')
aux_ops += [op_dipole_x, op_dipole_y, op_dipole_z]
# add user specified auxiliary operators
if aux_operators is not None:
for aux_op in aux_operators:
if hasattr(aux_op, 'name'):
name = aux_op.name
else:
name = ''
_add_aux_op(aux_op, name)
logger.info('Molecule num electrons: %s, remaining for processing: %s',
[num_alpha, num_beta], new_nel)
nspinorbs = qmolecule.num_orbitals * 2
new_nspinorbs = nspinorbs - len(freeze_list) - len(remove_list)
logger.info(
'Molecule num spin orbitals: %s, remaining for processing: %s',
nspinorbs, new_nspinorbs)
self._molecule_info['num_particles'] = (new_num_alpha, new_num_beta)
self._molecule_info['num_orbitals'] = new_nspinorbs
reduction = self._two_qubit_reduction if self._qubit_mapping == 'parity' else False
self._molecule_info['two_qubit_reduction'] = reduction
self._untapered_qubit_op = qubit_op
z2symmetries = Z2Symmetries([], [], [], None)
if self._z2symmetry_reduction is not None:
logger.debug('Processing z2 symmetries')
qubit_op, aux_ops, z2symmetries = self._process_z2symmetry_reduction(
qubit_op, aux_ops)
self._molecule_info['z2_symmetries'] = z2symmetries
logger.debug('Processing complete ready to run algorithm')
return qubit_op, aux_ops