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DEG THRESHOLD: Difference between revisions

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Created page with "{{TAGDEF|DEGEN_THR|[real]}} {{DEF|DEGEN_THR| 2*10^{-3} | }} Description: {{TAG|DEGEN_THR}} specifies whether two eigenvalues should be treated as degenerate during wavefunction clustering. {{TAG|DEGEN_THR}} is specified in units of eV. ---- This parameter is used to find clusters of wave functions within a given energy range. If it is set too high, non-degenerate eigenvalue pairs may be detected as degenerate pairs. Then, the inverse iteration will attempt to converge..."
 
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This parameter is used to find clusters of wave functions within a given energy range. If it is set too high, non-degenerate eigenvalue pairs may be detected as degenerate pairs. Then, the inverse iteration will attempt to converge them. Ultimately, the program will get stuck and converge poorly. Conversely, too small a value might not detect all degenerate eigenvalues. The most severe problems are caused by very narrow semicore bands.
This parameter is used to find clusters of wave functions within a given energy range. If it is set too high, non-degenerate eigenvalue pairs may be detected as degenerate pairs. Then, the inverse iteration will attempt to converge them. Ultimately, the program will get stuck and converge poorly. Conversely, too small a value might not detect all degenerate eigenvalues. The most severe problems are caused by very narrow semicore bands.


The {{FILE|POTCAR}} files contain a default {{TAG|ENMAX}} (and {{TAG|ENMIN}}). Therefore, it is, in principle, not necessary to specify {{TAG|ENCUT}} in the {{FILE|INCAR}} file.
{{NB|tip|If you experience large drifts in the Born effective charges and adding more k-points does not help, try adjusting this parameter.}}
For calculations with more than one species, the maximum cutoff {{TAG|ENMAX}} (or {{TAG|ENMIN}}) value is used for the calculation (see {{TAG|PREC}}).
 
{{NB|important|If you experience large drifts in the Born effective charges and adding more k-points does not help, try adjusting this parameter.}}
{{NB|mind|This tag is only available from VASP.6.6.1}}


== Related tags and articles ==
== Related tags and articles ==
{{TAG|ENMAX}},
{{TAG|LSUBROT}}
{{TAG|ENMIN}},
{{TAG|ENINI}},
{{TAG|ENAUG}},
{{TAG|PREC}},
{{TAG|NGX}},
{{TAG|NGY}},
{{TAG|NGZ}},
{{TAG|NGXF}},
{{TAG|NGYF}},
{{TAG|NGZF}},
{{FILE|POTCAR}}
 
{{sc|ENCUT|Examples|Examples that use this tag}}


[[Category:INCAR tag]][[Category:Projector-augmented-wave method]]
[[Category:INCAR tag]][[Category:Electronic minimization]]

Revision as of 15:28, 15 April 2026

DEGEN_THR = [real] 

Default: DEGEN_THR = 2*10^{-3}

Description: DEGEN_THR specifies whether two eigenvalues should be treated as degenerate during wavefunction clustering. DEGEN_THR is specified in units of eV.


This parameter is used to find clusters of wave functions within a given energy range. If it is set too high, non-degenerate eigenvalue pairs may be detected as degenerate pairs. Then, the inverse iteration will attempt to converge them. Ultimately, the program will get stuck and converge poorly. Conversely, too small a value might not detect all degenerate eigenvalues. The most severe problems are caused by very narrow semicore bands.



Related tags and articles

LSUBROT