GGA: Difference between revisions

From VASP Wiki
No edit summary
No edit summary
Line 8: Line 8:
Possible options are:
Possible options are:


No xc:
:No xc:
:{| border="1" cellspacing="0" cellpadding="5"
:{| border="1" cellspacing="0" cellpadding="5"
|No xc || Description
|No xc || Description

Revision as of 14:47, 9 April 2022

GGA = 91 | PE | RP | PS | AM | LIBXC
Default: GGA = exchange-correlation functional in accordance with the POTCAR file 

Description: GGA specifies a LDA or GGA exchange-correlation functional.


This tag was added to perform GGA calculation with pseudopotentials generated with conventional LDA reference configurations.

Important: VASP recalculates the exchange-correlation energy inside the PAW sphere and corrects the atomic energies given by the POTCAR file. For this to work, the original LEXCH tag must not be modified in the POTCAR file.

Possible options are:

No xc:
No xc Description
CO No exchange-correlation
LDA type Description
WI Wigner[1][2]
HL Hedin-Lundqvist[3]
CA Ceperley-Alder[4]
PZ Ceperley-Alder, parametrization of Perdew-Zunger[5]
VW vokso1980"/> (VWN)
LIBXC (or LI) Any LDA from Libxc[6][7][8]
GGA type Description
91 Perdew-Wang 91[9]
PE Perdew-Burke-Ernzerhof[10]
AM AM05[11][12][13]
RP Revised Perdew-Burke-Ernzerhof (RPBE)[14] with Pade Approximation
RE revPBE[15]
B3 B3LYP[16], where LDA part is with VWN3-correlation
B5 B3LYP, where LDA part is with VWN5-correlation
BF BEEF[17], xc (with libbeef)
PS Perdew-Burke-Ernzerhof revised for solids (PBEsol)
LIBXC (or LI) any GGA from Libxc[6][7][8]
Intended for vdW functionals:
OR optPBE
BO optB88
MK optB86b
Special settings for range-separated ACFDT:
RA new RPA Perdew Wang
03 range-separated ACFDT (LDA - sr RPA)
05 range-separated ACFDT (LDA - sr RPA)
10 range-separated ACFDT (LDA - sr RPA)
20 range-separated ACFDT (LDA - sr RPA)
PL new RPA+ Perdew Wang

The LIBXC tag (or just LI) allows to use a LDA or GGA functional from the library of exchange-correlation functionals Libxc[6][7][8]. Along with GGA=LIBXC, it is also necessary to specify the LIBXC1 and LIBXC2 tags that specify the particular functional. Note that it is necessary to have Libxc >= 5.2.0 installed and VASP.6.3.0 or higher compiled with precompiler options.

The AM05 functional and the PBEsol functional are constructed using different principles, but both aim at a decent description of yellium surface energies. In practice, they yield quite similar results for most materials. Both are available for spin-polarized calculations.

The special flags for range-separated RPA have not been extensively tested and should be used only after careful inspection of the source code. The flags allow to select range-separated ACFDT calculations, where a short-range local (DFT-like) exchange and correlation kernel is added to the long-range exchange and RPA correlation energy.

Examples that use this tag

References