Solver

linear_solver{} (optional)

Parameters for linear equation solver in current equation.

iterations (optional)

value:

integer

default:

10000

example:

200

number of iterations (optional)

abs_accuracy (optional)

value:

double

default:

1e-30 # [eV]

example:

1e-30 # [eV]

absolute accuracy of Fermi level, use a small value to force convergence

Note

abs_accuracy is (dimension dependent!!!): (default is: 1e-30 [eV] (1D), 1e-30 [eV] (2D), 1e-30 [eV] (3D))

rel_accuracy (optional)

value:

double, 0.0 <= rel_accuracy <= 0.01

default:

1e-13 # [dimensionless]

relative accuracy

(default is: 1e-13 [dimensionless]), 0.0 <= rel_accuracy <= 0.01

dkr_value (optional)

value:

double, must be <= 0.5

default:

-1.0 # [dimensionless]

example:

0.1 # [dimensionless]

A parameter to speed up calculations, affects preconditioning

Note

Negative values are ignored but will switch to a slightly slower but more stable preconditioning.

use_cscg (optional)

value:

yes or no

default:

no

Forces the slower but occasionally more robust CSCG (Composite Step Conjugate Gradient ) linear solver to be used rather than the cg (Conjugate Gradient) linear solver. May occasionally prevent a diagonalization failure.

force_diagonal_preconditioner (optional)

value:

yes or no

default:

no

Only for debugging purposes, enabling will make code much slower or prevent convergence. Forces the use of a slower but more robust diagonal preconditioner. Only for debugging purposes, enabling will make code much slower or prevent convergence. Please try setting it to yes in case preconditioning fails or the linear solver diverges. If set to yes, iterations may have to be further increased.

force_iteration (optional)

value:

yes or no

default:

no

Only for debugging purposes, enabling will make code much slower or prevent convergence.

extended_accuracy (optional)

value:

0 or 1

default:

0

If set to 1, then current equation is solved using slower but more accurate solver (only implemented for nonperiodic 1D simulations). Experimental feature, will change in the future.