Parameter: nleja

Definition

In the CAMELLIA component, we used the Newton-Leja interpolation algorithm to evaluate the local operator trace. Specially, the real leja points are used in the newton interpolation to evaluate

\[\exp( -\tau H ) |v\rangle\]

efficiently. Here $H$ is the local Hamiltonian, $|v\rangle$ the propagated vector, $\tau$ imaginary-time point. The nleja parameter is a key parameter to control the Newton-Leja algorithm. It means the maximum number of real leja points.

Type

Integer

Default value

64

Component

Only for the CAMELLIA component.

Behavior

Determine the size of involved arrays.

This Newton-Leja algorithm is unstable. Sometimes it is not easy to obtain convergence with the given leja points. At that time, you can increase nleja and redo the calculation.

Comment

The CAMELLIA component is not ready now.