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.