Wrong VBM and CBM in mobility calculation

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sponce
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Joined: Wed Jan 13, 2016 7:25 pm
Affiliation: EPFL

Re: Wrong VBM and CBM in mobility calculation

Post by sponce »

Does you calculation include SOC ?

If I understand correctly you have 32 electrons and 32 bands in your nscf. This means you only have occupied band. You have no unoccupied band.
Is this correct ?

If this is the case, you cannot expect to have a CB Fermi level.

Now if this is without SOC and you therefore have only 16 bands that are populated in NSCF.

In that case, the question is: did you skip band for doing the wannierization. If so, you have to indicate that with nbnskip.

The easiest would be to show us a plot with the nscf bandstructure and the Wannierzied bandstructure on top of it.
Prof. Samuel Poncé
Chercheur qualifié F.R.S.-FNRS / Professeur UCLouvain
Institute of Condensed Matter and Nanosciences
UCLouvain, Belgium
Web: https://www.samuelponce.com
sdwang

Re: Wrong VBM and CBM in mobility calculation

Post by sdwang »

I have not included SOC, and there is 16 bands and I set nbnd=32 in nscf. In epw.in the nbndsub=20 and nbndskip=0.
Now the problem is wrong VBM and CBM is OK since I moved scissor.
The band structures of DFT and Wannier interpolated is here.Image, or https://drive.google.com/file/d/1bBWtmgaI8Y0f_EQHIayxxclrl6FeIxNH/view?usp=sharing
Thanks.
sdwang

Re: Wrong VBM and CBM in mobility calculation

Post by sdwang »

Dear Samuel,
I use the dev-version of EPW and 'Warning: too many iterations in bisection' disappear now
but the VBM is still wrong.
Is there any suggestion?

Thanks!

SD
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