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I am using HSE06 hybrid functional to calculate the band structure. I copied IBZKPT file as the KPOINTS file and pasted the k point path for the band structure after this file. The k point path for the band structure was obtained by another band structure calculation with PBE functional for the same system before. The new KPOINTS files is shown below.

Automatically generated mesh
61
Reciprocal lattice
0.00000000000000 0.00000000000000 0.00000000000000 1
0.09090909090909 0.00000000000000 0.00000000000000 2
...
-0.09090909090909 0.45454545454546 0.00000000000000 2
0.00000000 0.00000000 0.00000000 0.000
...
0.50000000 0.50000000 0.00000000 0.000

The INCAR file is shown below.

ISTART = 1
LWAVE = .FALSE.
LCHARGE = .TRUE.
ICHARG = 11
IVDW = 12
ISPIN = 2
MAGMOM = 0.156 -0.155 -0.096 0.096 -0.156 0.155 -0.156 0.155 0.096\
-0.096 0.156 -0.155 -0.156 0.155 0.096 -0.096 0.156 -0.155\
0.156 -0.155 -0.096 0.096 -0.156 0.155
LORBIT = 11
ENCUT = 500
ISMEAR = 0
SIGMA = 0.03
PREC = Accurate
LHFCALC = .TRUE.
AEXX = 0.25
HFSCREEN = 0.2
ALGO = Damped
TIME = 0.4
PRECFOCK = Fast
ISYM = 3
LREAL = Auto
NELMIN = 5
NELM = 700
NELMDL = -10
EDIFF = 1e-5
NPAR = 32
KPAR= 16

After the NSCF calculation done, the band structure is completely wrong. I upload the band structure below, which I obtained through using p4v software to read vasprun.xml file from the non-self consistent calculation with the HSE06 hybrid functional.

enter image description here

The output file shows the warning information below.

| |
| W W AA RRRRR N N II N N GGGG !!! |
| W W A A R R NN N II NN N G G !!! |
| W W A A R R N N N II N N N G !!! |
| W WW W AAAAAA RRRRR N N N II N N N G GGG ! |
| WW WW A A R R N NN II N NN G G |
| W W A A R R N N II N N GGGG !!! |
| |
| Your generating k-point grid is not commensurate to the symmetry |
| of the lattice. This can cause slow convergence with respect |
| to k-points for HF type calculations |
| 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) |
| |
-----------------------------------------------------------------------------

I am doing the band structure calculation and I have to set up the k point path manually. I cannot use automatic k-point generation, which is used in single point calculation so I do not understand what VASP means by use automatic k-point generation in this band structure calculation step.

Would anyone please give me some suggestions on the solution?

Thank you very much.

Kieran

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As the error indicate:

| Your generating k-point grid is not commensurate to the symmetry |
| of the lattice. This can cause slow convergence with respect |
| to k-points for HF type calculations |
| 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) |

You need to define/use a correct k-point path.

As you already state that you can not use automatic k-point generation, the solution is:

  • Identify the crystal symmetry you are working on.
  • Look for the Brillouin zones of that symmetry.
  • Select the high symmetry points for the path.
  • Generate the k-point between each symmetry points.

Take o look here about how to accomplish these tasks.

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  • $\begingroup$ Thank you for the suggestion. Previously, I did the band structure calculation for this same crystal system with the PBE functional through the VASP code. In that previous band structure calculation, I used high-symmetry k point and the calculation was done successfully. After that, I re-did this calculation with the HSE06 hybrid functional and I used the high-symmetry k point, which I used in the previous calculation with PBE functional. I do not understand why the high-symmetry k point does not work in the calculation with HSE06 hybrid functional... $\endgroup$
    – Kieran
    Sep 27 at 14:43
  • $\begingroup$ ...while works in the calculation with PBE functional. Would you please give me more suggestions on the solution? (Reproduced from Kieran's comment since it got too long). $\endgroup$
    – Tyberius
    Sep 27 at 16:44
  • $\begingroup$ I really don't know expect such behavior. My only recommendation is to use a clean folder with the input files only and run the calculation again. $\endgroup$
    – Camps
    Sep 27 at 23:10

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