AEXX: Difference between revisions

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.

@@ Line 1: / Line 1: @@
 {{TAGDEF|AEXX|[real]}}
-{{DEF|AEXX|0.25|if {{TAG|LHFCALC}}{{=}}.TRUE.|0|otherwise}}
+{{DEF|AEXX|0.25|if {{TAG|LHFCALC}}{{=}}.TRUE.|0|if {{TAG|LHFCALC}}{{=}}.FALSE.}}
 Description: {{TAG|AEXX}} specifies the fraction of exact exchange in a Hartree-Fock-type/hybrid-functional calculation.
 ----
-{{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|
+*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.
-A comprehensive evaluation of the performance of the PBE0 functional, as compared to PBE, can be found in Ref. {{cite|paier:jcp:05}}.
+*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 {{TAG|AEXX}}=1.0, VASP sets by default {{TAG|ALDAC}}=0.0, {{TAG|AGGAC}}=0.0, and {{TAG|AMGGAC}}=0.0 and thus runs a full Hartree-Fock-type calculation.
 == Related tags and articles ==
@@ Line 19: / Line 17: @@
 {{TAG|LHFCALC}},
 {{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}}