AEXX: Difference between revisions

Revision as of 19:47, 17 October 2025

AEXX = [real]

Default: AEXX	= 0.25	if LHFCALC=.TRUE. .AND. LRHFCALC=.FALSE.
	= 1	if LRHFCALC=.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|if {{TAG|LHFCALC}}{{=}}.FALSE.}}
+{{DEF|AEXX|0.25|if {{TAG|LHFCALC}}{{=}}.TRUE. .AND. {{TAG|LRHFCALC}}{{=}}.FALSE.|1|if {{TAG|LRHFCALC}}{{=}}.TRUE.|0|if {{TAG|LHFCALC}}{{=}}.FALSE.}}
 Description: {{TAG|AEXX}} specifies the fraction of exact exchange in a Hartree-Fock-type/hybrid-functional calculation.
@@ Line 17: / Line 17: @@
 {{TAG|LHFCALC}},
 {{TAG|HFSCREEN}},
+{{TAG|LRHFCALC}},
 [[List_of_hybrid_functionals|List of hybrid functionals]],
 [[Hybrid_functionals:_formalism|Hybrid functionals: formalism]]