# VASP error when trying to do calculations in the presence of an electric field

I am trying to observe the effect of the electric field on 2D materials. I applied electric field by introducing three tags:

LDIPOL = .TRUE.
IDIPOL = 3   # for Z direction
EFIELD = X   # eV/A**


in INCAR, first in SCF and then in band structure calculation (NSCF).

Those are the same three lines (except in a different order), as what Tristan Maxson suggested in his answer to: Electric Field Calculations in VASP

But I could not get the reported results. Am I doing something wrong?

I am not getting any error, I am just unable to report the published data.

I applied electric field on stanene. After relaxing stanene with ISIF =4, I used EFIELD tags in sc and then in bands (ISTART =1, ICHARG = 11) calculations. For zero electric field, I am getting bandgap around 73.6 meV which is the same as reported. But as the electric field increases, the mismatch between values occurs. Like for E = 0.001eV/A, I am getting 71.1 meV and the reported one is 76.3 meV. For E = 1.0eV/A, I get 66.216 meV, and reported one is 318.3 meV

POSCAR:

Sn

1.0000000000000000

4.6730959813628878   -0.0000000228025768   -0.0000000000000001
2.3365474619415303    4.0470201968368267    0.0000000000000001
-0.0000000000000006    0.0000000000000005   19.2995674192802440
Sn

2

Direct

-0.0000000000000000  0.0000000000000000  0.4986167295676965
0.3333332607201882  0.3333333333333357  0.4545313204323064
0.00000000E+00      0.00000000E+00      0.00000000E+00
0.00000000E+00      0.00000000E+00      0.00000000E+00


• Welcome to our site. Could you share the error you are getting?
– Camps
Mar 1 '21 at 12:02
• Hi, you should show the comparison.
– Jack
Mar 1 '21 at 12:59
• The input lines in your question are exactly the same as the ones suggested by Tristan Maxson in this answer: mattermodeling.stackexchange.com/q/1700/5 but in a different order. I've now inserted that detail into your question. So are you saying that you tried that and it didn't work? If so, please show us the full input file and the full output file. Mar 1 '21 at 17:50
• It looks like you originally posted your edit as an answer. In the future, please add any clarification as an edit to your original post. It helps other users to have the whole of the question in the original post and only answers down below.
– Tyberius
Mar 15 '21 at 20:38

I assume that you have relaxed your geometry structure and can perform the VASP calculation. And I support the necessary input cards for SCF and NSCF calculations below.

• SCF calculation to obtain the converged charge density and wavefunction:

#General:
ISTART=0
ICHARG=2
ENCUT=450
EDIFF=1E-9
NELM=300
ISMEAR=-5
#SIGMA=0.05
IALGO=38

#Electric Field:
IDIPOL=3
LDIPOL=.TRUE.
EFIELD=0.2    # eV/Angstrom

• NSCF calculation to obtain bandstructure by reading previous charge density:

#General:
ISTART=0
ICHARG=11
ENCUT=450
EDIFF=1E-9
NELM=300
ISMEAR=0
SIGMA=0.05
IALGO=38

#Electric Field:
IDIPOL=3
LDIPOL=.TRUE.
EFIELD=0.2    # eV/Angstrom


Hope it helps.

• +1 so the problem is probably that the user put X instead of a number like 0.2 ? Mar 2 '21 at 3:50
• @NikeDattani I am not sure about that. I just show the right way to do that.
– Jack
Mar 2 '21 at 5:29