LRHFCALC: Difference between revisions

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{{TAGDEF|LRHFCALC|.TRUE. {{!}} .FALSE. |.FALSE.}}
{{TAGDEF|LRHFCALC|.TRUE. {{!}} .FALSE. |.FALSE.}}


Description: Switch on the decomposition of the exchange for the hybrid functionals using full Hartree-Fock exchange at long range, like [[Hybrid_functionals:_formalism#Error_function_screening_with_long-range_Hartree-Fock_exchange|RSHXLDA or RSHXPBE]].
Description: Switch on the decomposition of the exchange for the hybrid functionals using full Hartree-Fock exchange at long range.
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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, like for instance in RSHXLDA or RSHXPBE.{{cite|iikura:jcp:2001}}{{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:


The setting of the RSHXLDA and RSHXPBE functionals is shown on the [[list_of_hybrid_functionals|page listing the hybrid functionals]].
:<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|
{{NB|mind|
*If {{TAG|LRHFCALC}}{{=}}.TRUE., then {{TAG|LHFCALC}}{{=}}.TRUE. is automatically set.
*If {{TAG|LRHFCALC}}{{=}}.TRUE., then {{TAG|LHFCALC}}{{=}}.TRUE. is automatically set.

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:

[math]\displaystyle{ 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]\displaystyle{ a_{\mathrm{LR}} }[/math] and screening [math]\displaystyle{ \mu }[/math] 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:
Important: When AEXX=1 (the default for LRHFCALC=.TRUE.), the correlation [math]\displaystyle{ E_{\mathrm{c}}^{\mathrm{SL}} }[/math] is not included. However, it can be included by setting ALDAC=1.0 and AGGAC=1.0.

Related tags and articles

LHFCALC, HFSCREEN, AEXX, LMODELHF, LTHOMAS, list of hybrid functionals, Hybrid functionals: formalism

Examples that use this tag