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| Description: {{TAG|LRHFCALC}} specifies whether the only the long-range Hartree-Fock is used. | | Description: {{TAG|LRHFCALC}} specifies whether the only the long-range Hartree-Fock is used. |
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| If one does not specifically request a particular hybrid functional (see {{TAG|AEXX}}, {{TAG|ALDAX}}, {{TAG|ALDAC}}, {{TAG|AGGAX}}, {{TAG|AGGAC}}, {{TAG|AMGGAX}}, {{TAG|AMGGAC}}, and the section on [[list_of_hybrid_functionals|settings for specific hybrid functionals]]) VASP will default to the [[list_of_hybrid_functionals#PBE0|PBE0 hybrid functional]].
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| It is recommended to select a "direct optimization" algorithm for HF/DFT hybrid functonal type calculations, i.e., {{TAG|ALGO}}=Damped ({{TAG|IALGO}}=53) or {{TAG|ALGO}}=All ({{TAG|IALGO}}=58) in the {{FILE|INCAR}} file.
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| The blocked-Davidson algorithm {{TAG|ALGO}}=Normal is, with certain caveat, also supported, whereas calculations for the other algorithms ({{TAG|ALGO}}=Fast) are not properly supported (note: no warning is printed). The blocked-Davidson algorithm ({{TAG|ALGO}}=Normal) is generally rather slow, and in many cases the Pulay mixer will be unable to determine the proper ground-state. We hence recommend to select the blocked-Davidson algorithm only in combination with straight mixing or a Kerker like mixing (see the [[density_mixing|section on mixing]]). The following combination have been successfully applied for small and medium sized systems
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| {{TAG|LHFCALC}} = .TRUE. ; {{TAG|ALGO}} = Normal ; {{TAG|IMIX}} = 1 ; {{TAG|AMIX}} = a
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| Decrease the parameter a until convergence is reached.
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| In most cases, however, it is recommended to use the "Damped" algorithm with suitably chosen timestep. The following setup for the electronic optimization works reliably in most cases:
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| {{TAG|LHFCALC}} = .TRUE. ; {{TAG|ALGO}} = Damped ; {{TAG|TIME}} = 0.5
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| If convergence is not obtained, it is recommended to reduce the timestep {{TAG|TIME}}.
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| == Related tags and articles == | | == Related tags and articles == |
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| [[list_of_hybrid_functionals|settings for specific hybrid functionals]] | | [[list_of_hybrid_functionals|settings for specific hybrid functionals]] |
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| {{sc|LHFCALC|Examples|Examples that use this tag}} | | {{sc|LRHFCALC|Examples|Examples that use this tag}} |
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| [[Category:INCAR tag]][[Category:Exchange-correlation functionals]][[Category:Hybrid_functionals]] | | [[Category:INCAR tag]][[Category:Exchange-correlation functionals]][[Category:Hybrid_functionals]] |
