OperatorSpectrumConfig

class cuquantum.densitymat.OperatorSpectrumConfig(

min_krylov_block_size: int | None = None,

max_buffer_ratio: int | None = None,

max_restarts: int | None = None,

)

A data class for providing configuration options to the OperatorSpectrumSolver eigensolver.

min_krylov_block_size

Minimum number of Krylov subspace vectors to use in the block iterative method. A larger value may improve convergence but increases memory usage and computational cost. If not specified, a default value will be chosen. Defaults to 1.

Type:

int | None

max_buffer_ratio

Maximum ratio of the total number of blocks in the Krylov subspace to the number of requested eigenvalues. If not specified, a default value will be chosen. Must be greater than 1. Defaults to 5.

Type:

int | None

max_restarts

Maximum number of thick restarts of the block Krylov algorithm. The total number of Krylov-subspace expansions performed is at most max_restarts + 1 (one initial expansion plus up to max_restarts restarted expansions). A value of 0 corresponds to a single expansion with no restart. If not specified, a default value will be chosen. Defaults to 19 (i.e. up to 20 expansions).

Type:

int | None