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class qiskit.algorithms.EvolutionProblem(hamiltonian, time, initial_state=None, aux_operators=None, truncation_threshold=1e-12, t_param=None, param_value_dict=None)

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Bases: object(opens in a new tab)

Deprecated: Evolution problem class.

The EvolutionProblem class has been superseded by the qiskit.algorithms.time_evolvers.TimeEvolutionProblem class. This class will be deprecated in a future release and subsequently removed after that.

This class is the input to time evolution algorithms and must contain information on the total evolution time, a quantum state to be evolved and under which Hamiltonian the state is evolved.

Deprecated since version 0.24.0

The class qiskit.algorithms.evolvers.evolution_problem.EvolutionProblem is deprecated as of qiskit-terra 0.24.0. It will be removed no earlier than 3 months after the release date. Instead, use the class qiskit.algorithms.time_evolvers.TimeEvolutionProblem. See in a new tab) for a migration guide.


  • hamiltonian (OperatorBase) – The Hamiltonian under which to evolve the system.
  • time (float(opens in a new tab)) – Total time of evolution.
  • initial_state (StateFn |QuantumCircuit | None) – The quantum state to be evolved for methods like Trotterization. For variational time evolutions, where the evolution happens in an ansatz, this argument is not required.
  • aux_operators (ListOrDict[OperatorBase] | None) – Optional list of auxiliary operators to be evaluated with the evolved initial_state and their expectation values returned.
  • truncation_threshold (float(opens in a new tab)) – Defines a threshold under which values can be assumed to be 0. Used when aux_operators is provided.
  • t_param (Parameter | None) – Time parameter in case of a time-dependent Hamiltonian. This free parameter must be within the hamiltonian.
  • param_value_dict (dict(opens in a new tab)[Parameter, complex(opens in a new tab)] | None) – Maps free parameters in the problem to values. Depending on the algorithm, it might refer to e.g. a Hamiltonian or an initial state.


ValueError(opens in a new tab) – If non-positive time of evolution is provided.



Returns time.




Checks if all parameters present in the Hamiltonian are also present in the dictionary that maps them to values.


ValueError(opens in a new tab) – If Hamiltonian parameters cannot be bound with data provided.

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