My Community

I have successfully run a self-consistent calculation for a periodic supercell with an applied electric field using the EFIELD_PEAD tag. I now want to plot the bandstructure along selected high-symmetry directions.

Apparently, with EFIELD_PEAD on, VASP does not like the usual procedure for doing a non-self-consistent calculation with strings of k-points ("Your generating k-point grid is not commensurate to the symmetry of the lattice. etc.") and shuts down. Seeing as this is the same type of error generated for HF-type calculations, I tried the recommended procedure for that case where you essentially add the k-points (with zero weight) manually at the end of the IBZKPT from the self-consistent calculation and use this as the new KPOINTS file. I now get a different error:

| Your generating k-point grid is not commensurate to the symmetry |
| of the lattice. This does not sit well in combination with the |
| PEAD routines, sorry ... |
| suggested SOLUTIONS: |
| ) if not already the case, use automatic k-point generation |
| ) shift your grid to Gamma (G) (e.g. required for hex or fcc lattice) |

Is there a way to produce a bandstructure plot in this case (or is it simply an ill-posed question)?


My INCAR:

ISTART = 0
ISYM = 0
ENCUT = 500
PREC = High
ALGO = N
ISMEAR = 0
SIGMA = 0.05
LPLANE=.TRUE.
EFIELD_PEAD = 0.0 0.0 0.002 !in ev/A
TIME = 0.1

and KPOINTS:

Automatically generated mesh
182
Reciprocal lattice
0.00000000000000 0.00000000000000 0.00000000000000 1
0.09090909090909 0.00000000000000 0.00000000000000 2
0.18181818181818 0.00000000000000 0.00000000000000 2
...
...
...
0.05263158 0.00000000 0.00000000 0.0
0.02631579 0.00000000 0.00000000 0.0
0.00000000 0.00000000 0.00000000 0.0

hi, ashwin, I really want to know if it is necessary to set ISYM=0 when set EFIELD=0.1