qiskit.chemistry.algorithms.QEomEE

class QEomEE(operator, num_orbitals, num_particles, qubit_mapping='parity', two_qubit_reduction=True, active_occupied=None, active_unoccupied=None, is_eom_matrix_symmetric=True, se_list=None, de_list=None, z2_symmetries=None, untapered_op=None, aux_operators=None)

QEomEE algorithm (classical)

Parameters

• operator (LegacyBaseOperator) – qubit operator

• num_orbitals (int) – total number of spin orbitals, has a min. value of 1.

• num_particles (Union[List[int], int]) – number of particles, if it is a list, the first number is alpha and the second number if beta.

• qubit_mapping (str) – qubit mapping type

• two_qubit_reduction (bool) – two qubit reduction is applied or not

• active_occupied (Optional[List[int]]) – list of occupied orbitals to include, indices are 0 to n where n is num particles // 2

• active_unoccupied (Optional[List[int]]) – list of unoccupied orbitals to include, indices are 0 to m where m is (num_orbitals - num particles) // 2

• is_eom_matrix_symmetric (bool) – is EoM matrix symmetric

• se_list (Optional[List[List[int]]]) – single excitation list, overwrite the setting in active space

• de_list (Optional[List[List[int]]]) – double excitation list, overwrite the setting in active space

• z2_symmetries (Optional[Z2Symmetries]) – represent the Z2 symmetries

• untapered_op (Optional[LegacyBaseOperator]) – if the operator is tapered, we need untapered operator to build element of EoM matrix

• aux_operators (Optional[List[LegacyBaseOperator]]) – Auxiliary operators to be evaluated at each eigenvalue

Raises

ValueError – invalid parameter

__init__(operator, num_orbitals, num_particles, qubit_mapping='parity', two_qubit_reduction=True, active_occupied=None, active_unoccupied=None, is_eom_matrix_symmetric=True, se_list=None, de_list=None, z2_symmetries=None, untapered_op=None, aux_operators=None)

Parameters

• operator (LegacyBaseOperator) – qubit operator

• num_orbitals (int) – total number of spin orbitals, has a min. value of 1.

• num_particles (Union[List[int], int]) – number of particles, if it is a list, the first number is alpha and the second number if beta.

• qubit_mapping (str) – qubit mapping type

• two_qubit_reduction (bool) – two qubit reduction is applied or not

• active_occupied (Optional[List[int]]) – list of occupied orbitals to include, indices are 0 to n where n is num particles // 2

• active_unoccupied (Optional[List[int]]) – list of unoccupied orbitals to include, indices are 0 to m where m is (num_orbitals - num particles) // 2

• is_eom_matrix_symmetric (bool) – is EoM matrix symmetric

• se_list (Optional[List[List[int]]]) – single excitation list, overwrite the setting in active space

• de_list (Optional[List[List[int]]]) – double excitation list, overwrite the setting in active space

• z2_symmetries (Optional[Z2Symmetries]) – represent the Z2 symmetries

• untapered_op (Optional[LegacyBaseOperator]) – if the operator is tapered, we need untapered operator to build element of EoM matrix

• aux_operators (Optional[List[LegacyBaseOperator]]) – Auxiliary operators to be evaluated at each eigenvalue

Raises

ValueError – invalid parameter

Methods

__init__(operator, num_orbitals, num_particles)	type operator LegacyBaseOperator
compute_minimum_eigenvalue([operator, …])	Computes minimum eigenvalue.
run()	Execute the classical algorithm.
supports_aux_operators()	Whether computing the expectation value of auxiliary operators is supported.

Attributes

aux_operators	Returns the auxiliary operators.
filter_criterion	returns the filter criterion if set
operator	Return the operator.
random	Return a numpy random.

property aux_operators

Returns the auxiliary operators.

Return type

Optional[List[Optional[OperatorBase]]]

compute_minimum_eigenvalue(operator=None, aux_operators=None)

Computes minimum eigenvalue. Operator and aux_operators can be supplied here and if not None will override any already set into algorithm so it can be reused with different operators. While an operator is required by algorithms, aux_operators are optional. To ‘remove’ a previous aux_operators array use an empty list here.

Parameters

• operator (Union[OperatorBase, LegacyBaseOperator, None]) – If not None replaces operator in algorithm

• aux_operators (Optional[List[Union[OperatorBase, LegacyBaseOperator, None]]]) – If not None replaces aux_operators in algorithm

Return type

MinimumEigensolverResult

Returns

MinimumEigensolverResult

property filter_criterion

returns the filter criterion if set

Return type

Optional[Callable[[Union[List, ndarray], float, Optional[List[float]]], bool]]

property operator

Return the operator.

Return type

Optional[OperatorBase]

property random

Return a numpy random.

run()

Execute the classical algorithm.

Returns

results of an algorithm.

Return type

dict

classmethod supports_aux_operators()

Whether computing the expectation value of auxiliary operators is supported.

If the minimum eigensolver computes an eigenstate of the main operator then it can compute the expectation value of the aux_operators for that state. Otherwise they will be ignored.

Return type

bool

Returns

True if aux_operator expectations can be evaluated, False otherwise