LRHFCALC: Difference between revisions

Latest revision as of 12:38, 9 February 2026

LRHFCALC = .TRUE. | .FALSE.
Default: LRHFCALC = .FALSE.

Description: Switch on the decomposition of the exchange for the hybrid functionals using full Hartree-Fock exchange at long range.

If LRHFCALC=.TRUE. the exchange functional is decomposed into short-range LDA, PBE or PBEsol (GGA=CA, PE, PS, respectively) and long-range Hartree-Fock:

E_{x c}^{h y b r i d} = a_{L R} E_{x, L R}^{H F} (μ) + E_{x, S R}^{S L} (μ) + (1 - a_{L R}) E_{x, L R}^{S L} (μ) + E_{c}^{S L}

The mixing $a_{L R}$ and screening $μ$ are controlled by the AEXX and HFSCREEN tags, respectively. The RSHXLDA or RSHXPBE functionals^[1]^[2]^[3] are examples of such functionals and their settings are shown on the page listing the hybrid functionals.

Mind:

If LRHFCALC=.TRUE., then LHFCALC=.TRUE. is automatically set.
If LRHFCALC=.TRUE., then AEXX=1 is automatically set, but AEXX can be set to another value.

Important: When AEXX=1 (the default for LRHFCALC=.TRUE.), the correlation

E_{c}^{S L}

is not included. However, it can be included by setting ALDAC=1.0 and AGGAC=1.0.

@@ Line 1: / Line 1: @@
 {{TAGDEF|LRHFCALC|.TRUE. {{!}} .FALSE. |.FALSE.}}
-Description: {{TAG|LRHFCALC}} selects a decomposition of the exchange functional for calculations with the [[:Category:Hybrid_functionals|range-separated hybrid RSHX functional]].
+Description: Switch on the decomposition of the exchange for the hybrid functionals using full Hartree-Fock exchange at long range.
 ----
-If {{TAG|LRHFCALC}}=.TRUE. the exchange operator is decomposed into short-range LDA (or PBE) and long-range Hartree-Fock parts for calculations with the range-separated hybrid RSHX functional.{{cite|gerber:cpl:2005}}{{cite|gerber:jcp:2007}} The screening parameter is specified by means of the {{TAG|HFSCREEN}} tag.
+If {{TAG|LRHFCALC}}=.TRUE. the exchange functional is decomposed into short-range LDA, PBE or PBEsol ({{TAG|GGA}}{{=}}CA, PE, PS, respectively) and long-range Hartree-Fock:
+:<math>E_{\mathrm{xc}}^{\mathrm{hybrid}}=a_{\mathrm{LR}} E_{\mathrm{x,LR}}^{\mathrm{HF}}(\mu) + E_{\mathrm{x,SR}}^{\mathrm{SL}}(\mu) + (1-a_{\mathrm{LR}})E_{\mathrm{x,LR}}^{\mathrm{SL}}(\mu) + E_{\mathrm{c}}^{\mathrm{SL}}</math>
+The mixing <math>a_{\mathrm{LR}}</math> and screening <math>\mu</math> are controlled by the {{TAG|AEXX}} and {{TAG|HFSCREEN}} tags, respectively. The RSHXLDA or RSHXPBE functionals{{cite|iikura:jcp:2001}}{{cite|gerber:cpl:2005}}{{cite|gerber:jcp:2007}} are examples of such functionals and
+their settings are shown on the [[list_of_hybrid_functionals|page listing the hybrid functionals]].
 {{NB|mind|
-*By default, {{TAG|AEXX}}{{=}}1 for the RSHX functional, but {{TAG|AEXX}} can be set to another value.
+*If {{TAG|LRHFCALC}}{{=}}.TRUE., then {{TAG|LHFCALC}}{{=}}.TRUE. is automatically set.
-*Only LDA ({{TAG|GGA}}{{=}}CA or PZ) or PBE ({{TAG|GGA}}{{=}}PBE) can be used for the short-range density functional part.}}
+*If {{TAG|LRHFCALC}}{{=}}.TRUE., then {{TAG|AEXX}}{{=}}1 is automatically set, but {{TAG|AEXX}} can be set to another value.}}
+{{NB|important|When {{TAG|AEXX}}{{=}}1 (the default for {{TAG|LRHFCALC}}{{=}}.TRUE.), the correlation <math>E_{\mathrm{c}}^{\mathrm{SL}}</math> is not included. However, it can be included by setting {{TAG|ALDAC}}{{=}}1.0 and {{TAG|AGGAC}}{{=}}1.0.}}
 == Related tags and articles ==
@@ Line 13: / Line 18: @@
 {{TAG|HFSCREEN}},
 {{TAG|AEXX}},
+{{TAG|LMODELHF}},
 {{TAG|LTHOMAS}},
-[[list_of_hybrid_functionals|list_of_hybrid_functionals]]
+[[list_of_hybrid_functionals|list of hybrid functionals]],
+[[Hybrid_functionals:_formalism|Hybrid functionals: formalism]]
 {{sc|LRHFCALC|Examples|Examples that use this tag}}