Lanczos

The Lanczos method for determining the lowest eigenmode.

[Lanczos] Options

tolerance: This is the convergence critera for relative change in the estimated lowest eigenvalue.

default: 0.01

max_iterations: The maximum number of refinement iterations when calculating the minimum eigenvalue.

default: 20

quit_early: If the relative change between the previous lowest eigenvalue and the curvature along the initial direction is less than tolerance terminate.

default: true