qiskit.chemistry.algorithms.QEOM¶

class QEOM(ground_state_solver, excitations='sd')[source]¶

The calculation of excited states via the qEOM algorithm

Parameters

ground_state_solver (GroundStateSolver) – a GroundStateSolver object. The qEOM algorithm will use this ground state to compute the EOM matrix elements
excitations (Union[str, List[List[int]]]) – The excitations to be included in the eom pseudo-eigenvalue problem. If a string (‘s’, ‘d’ or ‘sd’) then all excitations of the given type will be used. Otherwise a list of custom excitations can directly be provided.

__init__(ground_state_solver, excitations='sd')[source]¶

Parameters

ground_state_solver (GroundStateSolver) – a GroundStateSolver object. The qEOM algorithm will use this ground state to compute the EOM matrix elements
excitations (Union[str, List[List[int]]]) – The excitations to be included in the eom pseudo-eigenvalue problem. If a string (‘s’, ‘d’ or ‘sd’) then all excitations of the given type will be used. Otherwise a list of custom excitations can directly be provided.

Methods

__init__(ground_state_solver[, excitations])

type ground_state_solver: GroundStateSolver

solve(driver[, aux_operators])

Run the excited-states calculation.

Attributes

excitations

Returns the excitations to be included in the eom pseudo-eigenvalue problem.

property excitations¶

Returns the excitations to be included in the eom pseudo-eigenvalue problem.

Return type: Union[str, List[List[int]]]

solve(driver, aux_operators=None)[source]¶

Run the excited-states calculation.

Construct and solves the EOM pseudo-eigenvalue problem to obtain the excitation energies and the excitation operators expansion coefficients.

Parameters

driver (BaseDriver) – a chemistry driver object which defines the chemical problem that is to be solved by this calculation.
aux_operators (Union[List[FermionicOperator], List[BosonicOperator], None]) – Additional auxiliary operators to evaluate. Must be of type FermionicOperator if the qubit transformation is fermionic and of type BosonicOperator it is bosonic.

Return type

Union[ElectronicStructureResult, VibronicStructureResult]

Returns

The excited states result. In case of a fermionic problem a ElectronicStructureResult is returned and in the bosonic case a VibronicStructureResult.