Wrong result from band structure calculation

Message

agupta16 · #1 Post by **agupta16** » Tue Oct 25, 2011 4:51 am

Hi,

i am trying to plot the band structure for ZnO bulk but I am getting nonsense results as in it shows no band gap. I am a new user and am not familiar with fine nuances of the program so could somebody please help me identify that what is wrong with the INCAR and KPOINTS file which I am using to plot band structure.

INCAR file
PREC = Normal
ENCUT = 520.000
IBRION = -1
NSW = 0
ALGO = Normal (blocked Davidson)
NELM = 60
NELMIN = 2
EDIFF = 1.0e-05
EDIFFG = -0.02
VOSKOWN = 1
NBLOCK = 1
ISPIN = 1
INIWAV = 1
ISTART = 0
ICHARG = 11
LWAVE = .FALSE.
LCHARG = .TRUE.
ADDGRID = .TRUE.
ISMEAR = 1
SIGMA = 0.2
LREAL = .FALSE.
RWIGS = 1.25 0.73
LORBIT = 11

and KPOINTS file

high symmtery
11
Line Mode
reciprocal
0.0 0.0 0.0 !G
0.0 0.0 0.5 !A

0.0 0.0 0.5 !A
0.33333 0.33333 0.5 !H

0.33333 0.33333 0.5 !H
0.33333 0.33333 0.0 !K

0.33333 0.33333 0.0 !K
0.0 0.0 0.0 !G

I would really appreciate if someone could help me understand what am I doing wrong here.

Thanks

Dr Vitaly V. G. Chaban · #2 Post by **Dr Vitaly V. G. Chaban** » Tue Oct 25, 2011 5:56 am

Maybe the geometry of your bulk ZnO is not appropriate?

hatdau · #3 Post by **hatdau** » Fri Nov 04, 2011 2:16 am

First you should check your crystal structure to see if it's right.

Second there some suggestion for your band structure calculation:
1. First do scf then start band calculation with:
ISTART = 1
ICHARG = 11
ISMEAR = 0

* it is suggested to avoid using ISMEAR > 0 for insulator (http://cms.mpi.univie.ac.at/vasp/guide/ ... 0000000000)

Let us know the results.

Best,