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I'm trying to calculate frequencies of methane adsorbed on Ni, I'm using vdW-DF functional of Langreth (GGA=OR and PBE POTCAR).
VASP 5.2.12
K-POINT Gamma-point (3x3x1)
(I tried with 5x5x1) --> No changes

POSCAR
Converged geometry (forces < 0.01)

INCAR
ISPIN = 2; PREC = Accurate; ICHARG = 2 (or 11, no changes); MAGMON(5*0 -methane- 24*1 -24 metallic atoms-); ISYM=0; ENCUT = 415 (or 500, no changes); EDIFF=1E-7; LREAL=FALSE (TRU no changes); NGX =50, NGY = 48, NGZ = 114; EDIFFG = -1E-2; ALGO=Normal (V, F, no changes); ISMEAR= -1; SIGMA=0.1; POTIM (0.01, different values, no changes)

grep sigma OUTCAR indicates the following:

energy without entropy = 731.22799556 energy(sigma->0) = 730.61010942
energy without entropy = 144.02130953 energy(sigma->0) = 143.48464945
energy without entropy = 33.80689416 energy(sigma->0) = 33.28309139
energy without entropy = 21.22638124 energy(sigma->0) = 20.66892622
energy without entropy = 20.64573328 energy(sigma->0) = 20.06937195
energy without entropy = 6665.01581497 energy(sigma->0) = 6664.26886530
energy without entropy = 8502.97566115 energy(sigma->0) = 8502.74944085
energy without entropy = 9429.35611961 energy(sigma->0) = 9428.94345517
energy without entropy = 9989.37559612 energy(sigma->0) = 9989.12526016
energy without entropy = 11029.80146468 energy(sigma->0) = 11029.61995108
energy without entropy = 13373.99834060 energy(sigma->0) = 13373.97995623


The values are terrible!


Curiously, calculation of free molecule falls with LREAL=T and it works fine LREAL=F; With GGA=PE I see the same behaviour.

Thank you, I don't if the problem is la libraries, the compilation, the software version, a bug.

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