ENCUTFOCK: Difference between revisions

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{{TAG|PREC}},
{{TAG|PREC}},
{{TAG|ENCUT}},
{{TAG|ENCUT}},
[[list_of_hybrid_functionals|settings for specific hybrid functionals]]
[[list_of_hybrid_functionals|List of hybrid functionals]],
[[Hybrid_functionals:_formalism|Hybrid functionals: formalism]]


{{sc|ENCUTFOCK|Examples|Examples that use this tag}}
{{sc|ENCUTFOCK|Examples|Examples that use this tag}}

Latest revision as of 09:14, 18 October 2023

ENCUTFOCK = [real] 

Default: none

Description: The ENCUTFOCK tag sets the energy cutoff that determines the FFT grids used by the Hartree-Fock routines.


The flag ENCUTFOCK is no longer supported in VASP.5.2.4 and newer versions. Please use PRECFOCK instead.


The only sensible value for ENCUTFOCK is ENCUTFOCK=0. This implies that the smallest possible FFT grid, which just encloses the cutoff sphere corresponding to the plane wave cutoff, is used. This accelerates the calculations by roughly a factor two to three, but causes slight changes in the total energies and some noise in the calculated forces. The FFT grid used internally in the exact exchange (Hartree-Fock) routines is written to the OUTCAR file. Simply search for lines starting with

FFT grid for exact exchange (Hartree Fock)


In many cases, a sensible approach is to determine the electronic and ionic groundstate using ENCUTFOCK=0, and to make one final total energy calculation without the flag ENCUTFOCK.

Related tags and articles

PRECFOCK, PREC, ENCUT, List of hybrid functionals, Hybrid functionals: formalism

Examples that use this tag