DIAGONALIZATION

Set up type and parameters for Kohn-Sham matrix diagonalization. [Edit on GitHub]

Subsections

Keywords

Keyword descriptions

SECTION_PARAMETERS: logical = F

Lone keyword: T

Usage: &DIAGONALIZATION T

controls the activation of the diagonalization method [Edit on GitHub]

ALGORITHM: enum = STANDARD

Usage: ALGORITHM STANDARD

Valid values:

  • STANDARD Standard diagonalization: LAPACK methods or Jacobi.

  • OT Iterative diagonalization using OT method

  • LANCZOS Block Krylov-space approach to self-consistent diagonalisation

  • DAVIDSON Preconditioned blocked Davidson

  • FILTER_MATRIX Filter matrix diagonalization

Algorithm to be used for diagonalization [Edit on GitHub]

EPS_ADAPT: real = 0.00000000E+000

Usage: EPS_ADAPT 0.01

Required accuracy in iterative diagonalization as compared to current SCF convergence [Edit on GitHub]

EPS_ITER: real = 1.00000000E-008

Usage: EPS_ITER 1.e-8

Required accuracy in iterative diagonalization [Edit on GitHub]

EPS_JACOBI: real = 0.00000000E+000

Usage: EPS_JACOBI 1.0E-5

References: Stewart1982

Below this threshold value for the SCF convergence the pseudo-diagonalization method using Jacobi rotations is activated. This method is much faster than a real diagonalization and it is even speeding up while achieving full convergence. However, it needs a pre-converged wavefunction obtained by at least one real diagonalization which is further optimized while keeping the original eigenvalue spectrum. The MO eigenvalues are NOT updated. The method might be useful to speed up calculations for large systems e.g. using a semi-empirical method. [Edit on GitHub]

JACOBI_THRESHOLD: real = 1.00000000E-007

Usage: JACOBI_THRESHOLD 1.0E-6

References: Stewart1982

Controls the accuracy of the pseudo-diagonalization method using Jacobi rotations [Edit on GitHub]

MAX_ITER: integer = 2

Usage: MAX_ITER 20

Maximum number of iterations in iterative diagonalization [Edit on GitHub]