DIAGONALIZATION

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

Keywords

Keyword descriptions

SECTION_PARAMETERS

Type: logical
Default: F
Lone keyword: T
Usage: &DIAGONALIZATION T

Description: controls the activation of the diagonalization method

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ALGORITHM

Type: enum
Default: STANDARD
Usage: ALGORITHM STANDARD

Description: Algorithm to be used for diagonalization

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

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EPS_ADAPT

Type: real
Default: 0.00000000E+000
Usage: EPS_ADAPT 0.01

Description: Required accuracy in iterative diagonalization as compared to current SCF convergence

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EPS_ITER

Type: real
Default: 1.00000000E-008
Usage: EPS_ITER 1.e-8

Description: Required accuracy in iterative diagonalization

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EPS_JACOBI

Type: real
Default: 0.00000000E+000
Usage: EPS_JACOBI 1.0E-5

Description: 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.

References: Stewart1982

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JACOBI_THRESHOLD

Type: real
Default: 1.00000000E-007
Usage: JACOBI_THRESHOLD 1.0E-6

Description: Controls the accuracy of the pseudo-diagonalization method using Jacobi rotations

References: Stewart1982

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MAX_ITER

Type: integer
Default: 2
Usage: MAX_ITER 20

Description: Maximum number of iterations in iterative diagonalization

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