AEXX: Difference between revisions

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Description: {{TAG|AEXX}} specifies the fraction of exact exchange in a Hartree-Fock-type/hybrid-functional calculation.
Description: {{TAG|AEXX}} specifies the fraction of exact exchange in a Hartree-Fock-type/hybrid-functional calculation.
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{{NB|mind|For versions of VASP prior to 6.4.0, {{TAG|ALDAX}} was constrained to be equal to 1.0-{{TAG|AEXX}}. This constraint is lifted since VASP.6.4.0.}}
{{NB|mind|
{{NB|mind|For {{TAG|AEXX}}{{=}}1.0, VASP switches off correlation by default ({{TAG|ALDAC}}{{=}}0.0, {{TAG|AGGAC}}{{=}}0.0, and {{TAG|AMGGAC}}{{=}}0.0) and thus runs a full Hartree-Fock calculation.}}
*For versions of VASP prior to 6.4.0, {{TAG|ALDAX}} was constrained to be equal to 1.0-{{TAG|AEXX}}. This constraint is lifted since VASP.6.4.0.
*For {{TAG|AEXX}}{{=}}1.0, VASP switches off correlation by default ({{TAG|ALDAC}}{{=}}0.0, {{TAG|AGGAC}}{{=}}0.0, and {{TAG|AMGGAC}}{{=}}0.0) and thus runs a full Hartree-Fock calculation.}}


== Related tags and articles ==
== Related tags and articles ==
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{{TAG|LHFCALC}},
{{TAG|LHFCALC}},
{{TAG|HFSCREEN}},
{{TAG|HFSCREEN}},
[[List_of_hybrid_functionals|List of hybrid functionals]]
[[List_of_hybrid_functionals|List of hybrid functionals]],
[[Hybrid_functionals:_formalism|Hybrid functionals: formalism]]


{{sc|AEXX|Examples|Examples that use this tag}}
{{sc|AEXX|Examples|Examples that use this tag}}

Latest revision as of 08:28, 18 October 2023

AEXX = [real] 

Default: AEXX = 0.25 if LHFCALC=.TRUE.
= 0 if LHFCALC=.FALSE.

Description: AEXX specifies the fraction of exact exchange in a Hartree-Fock-type/hybrid-functional calculation.


Mind:
  • For versions of VASP prior to 6.4.0, ALDAX was constrained to be equal to 1.0-AEXX. This constraint is lifted since VASP.6.4.0.
  • For AEXX=1.0, VASP switches off correlation by default (ALDAC=0.0, AGGAC=0.0, and AMGGAC=0.0) and thus runs a full Hartree-Fock calculation.

Related tags and articles

ALDAX, ALDAC, AGGAX, AGGAC, AMGGAX, AMGGAC, LHFCALC, HFSCREEN, List of hybrid functionals, Hybrid functionals: formalism

Examples that use this tag

References