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

Description: GGA specifies the type of generalized-gradient-approximation one wishes to use.

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

Possible options are:

GGA Description
91 Perdew - Wang 91[1]
PE Perdew-Burke-Ernzerhof[2]
AM AM05[3][4][5]
HL Hendin-Lundqvist[6]
CA Ceperley-Alder[7]
PZ Ceperley-Alder, parametrization of Perdew-Zunger[8]
WI Wigner[9]
RP revised Perdew-Burke-Ernzerhof (RPBE)[10] with Pade Approximation
RE revPBE[11]
VW Vosko-Wilk-Nusair[12] (VWN)
B3 B3LYP[13], where LDA part is with VWN3-correlation
B5 B3LYP, where LDA part is with VWN5-correlation
BF BEEF[14], xc (with libbeef)
CO no exchange-correlation
PS Perdew-Burke-Ernzerhof revised for solids (PBEsol)[15]
intended for vdW functionals:
OR optPBE[16]
BO optB88[16]
MK optB86b[16]
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 tags AM (AM05) and PS (PBEsol) are only supported by VASP.5.X. 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