Issue with Ti_sv PPS and RPBE functional
Posted: Tue Jan 20, 2015 1:35 pm
Greetings,
I'm having a strange problem when computing the adsorption energy for titanium oxide.
I'm using the Ti_sv PPS with the RPBE functional, VASP version 5.3.3 (but I've also tested the thing on a 5.2.12)
The simulations of the system (Ionic Optimization) with the adsorbed molecule and the clean surface terminate without problems.
However, when I compute the adsorption energy (E_sys - E_surface -E_mol) I obtain an endothermic value of 0.57.
Please notice that I've ran the same calculations with (PBE + Ti_sv) and (RPBE + Ti_pv) and in both cases the adsorption energy is exothermic of around (1.4-1.9 eV), as it should be.
When I've used the same PPS (Ti_pv or Ti_sv) the final structures (both of the adsorbed and the clean surface) are pratically the same (coordinate difference < 0.0035).
I remember I had some other issues with RPBE functionals as it seems the case, did anyone had problems with that?
Other notes:
I have a vacancy in the surface and two delocalized electrons, I have used the LDA+U and magnetic moment plus spin polarized calculations. However the final magnetization is the same for the systems and I have used the same INCAR for every calculation. I've applied grimme vdW-D2 for the dispersions.
INCAR (ADSORBED)
ISTART = 0
ICHARG = 2
ISPIN = 2
GGA = PE ##I have changed this for RPBE
ENCUT = 400
MAGMOM = 29*0.0 1*1.0 3*0.0 2*1.0 5*0.0 81*0.0 2*0.0 6*0.0
ISMEAR = 0
SIGMA = 0.05
LDIPOL = .TRUE.
IDIPOL = 3
LREAL = AUTO
ALGO = NORMAL
EDIFF = 1E-5
NELMIN = 8
NELM = 250
EDIFFG = 1E-3
NSW = 400
IBRION = 1
POTIM = 0.2
LWAVE = .FALSE.
LCHARG = .FALSE.
LVDW = .TRUE.
NPAR = 2
NSIM = 2
LDAU = .TRUE.
LASPH = .TRUE.
LDAUL = 3 -1 -1 -1
LDAUU = 5.2 0.0 0.0 0.0
LDAUJ = 1.0 0.0 0.0 0.0
LMAXMIX = 4
LORBIT = 11
INCAR (surface):
ISTART = 0
ICHARG = 2
ISPIN = 2
GGA = PE
ENCUT = 400
MAGMOM = 29*0.0 1*1.0 3*0.0 2*1.0 5*0.0 79*0.0
ISMEAR = 0
SIGMA = 0.05
LDIPOL = .TRUE.
IDIPOL = 3
LREAL = AUTO
ALGO = NORMAL
EDIFF = 1E-5
NELMIN = 8
NELM = 250
EDIFFG = 1E-3
NSW = 400
IBRION = 1
POTIM = 0.2
LWAVE = .FALSE.
LCHARG = .FALSE.
LVDW = .TRUE.
NPAR = 2
NSIM = 2
LDAU = .TRUE.
LASPH = .TRUE.
LDAUL = 3 -1
LDAUU = 5.2 0.0
LDAUJ = 1.0 0.0
LMAXMIX = 4
LORBIT = 11
Thanks in advance!
I'm having a strange problem when computing the adsorption energy for titanium oxide.
I'm using the Ti_sv PPS with the RPBE functional, VASP version 5.3.3 (but I've also tested the thing on a 5.2.12)
The simulations of the system (Ionic Optimization) with the adsorbed molecule and the clean surface terminate without problems.
However, when I compute the adsorption energy (E_sys - E_surface -E_mol) I obtain an endothermic value of 0.57.
Please notice that I've ran the same calculations with (PBE + Ti_sv) and (RPBE + Ti_pv) and in both cases the adsorption energy is exothermic of around (1.4-1.9 eV), as it should be.
When I've used the same PPS (Ti_pv or Ti_sv) the final structures (both of the adsorbed and the clean surface) are pratically the same (coordinate difference < 0.0035).
I remember I had some other issues with RPBE functionals as it seems the case, did anyone had problems with that?
Other notes:
I have a vacancy in the surface and two delocalized electrons, I have used the LDA+U and magnetic moment plus spin polarized calculations. However the final magnetization is the same for the systems and I have used the same INCAR for every calculation. I've applied grimme vdW-D2 for the dispersions.
INCAR (ADSORBED)
ISTART = 0
ICHARG = 2
ISPIN = 2
GGA = PE ##I have changed this for RPBE
ENCUT = 400
MAGMOM = 29*0.0 1*1.0 3*0.0 2*1.0 5*0.0 81*0.0 2*0.0 6*0.0
ISMEAR = 0
SIGMA = 0.05
LDIPOL = .TRUE.
IDIPOL = 3
LREAL = AUTO
ALGO = NORMAL
EDIFF = 1E-5
NELMIN = 8
NELM = 250
EDIFFG = 1E-3
NSW = 400
IBRION = 1
POTIM = 0.2
LWAVE = .FALSE.
LCHARG = .FALSE.
LVDW = .TRUE.
NPAR = 2
NSIM = 2
LDAU = .TRUE.
LASPH = .TRUE.
LDAUL = 3 -1 -1 -1
LDAUU = 5.2 0.0 0.0 0.0
LDAUJ = 1.0 0.0 0.0 0.0
LMAXMIX = 4
LORBIT = 11
INCAR (surface):
ISTART = 0
ICHARG = 2
ISPIN = 2
GGA = PE
ENCUT = 400
MAGMOM = 29*0.0 1*1.0 3*0.0 2*1.0 5*0.0 79*0.0
ISMEAR = 0
SIGMA = 0.05
LDIPOL = .TRUE.
IDIPOL = 3
LREAL = AUTO
ALGO = NORMAL
EDIFF = 1E-5
NELMIN = 8
NELM = 250
EDIFFG = 1E-3
NSW = 400
IBRION = 1
POTIM = 0.2
LWAVE = .FALSE.
LCHARG = .FALSE.
LVDW = .TRUE.
NPAR = 2
NSIM = 2
LDAU = .TRUE.
LASPH = .TRUE.
LDAUL = 3 -1
LDAUU = 5.2 0.0
LDAUJ = 1.0 0.0
LMAXMIX = 4
LORBIT = 11
Thanks in advance!