Fermi level shift after Wannierization

Queries about input and output files, running specific calculations, etc.


Moderators: Global Moderator, Moderator

Post Reply
Message
Author
ahsan_javed
Newbie
Newbie
Posts: 27
Joined: Mon Jun 27, 2022 11:37 am

Fermi level shift after Wannierization

#1 Post by ahsan_javed » Fri Nov 17, 2023 1:04 pm

1. Band structure from DFT calculations
2. Wannier Band structure of step 1
..
When i plot these two band structures (BS) simultaneously, there is a shift in fermi energy and BS didn't overlap, and fermi level is not zero in both cases. Is it how it should be?

henrique_miranda
Global Moderator
Global Moderator
Posts: 497
Joined: Mon Nov 04, 2019 12:41 pm
Contact:

Re: Fermi level shift after Wannierization

#2 Post by henrique_miranda » Fri Nov 17, 2023 3:48 pm

The eigenvalues you get from Wannierization should not be shifted with respect to the eigenvalues you computed in VASP.
What you describe might happen if at some point you shift one of the band-structure and not the other.
Have a look at the eigenvalues in the OUTCAR file and compare with the eigenvalues you get from Wannier90.
Could you share the OUTCAR file, the wannier90.eig and your final data files + plotting scripts you use to plot the band-structure?

ahsan_javed
Newbie
Newbie
Posts: 27
Joined: Mon Jun 27, 2022 11:37 am

Re: Fermi level shift after Wannierization

#3 Post by ahsan_javed » Tue Nov 21, 2023 7:10 am

Relevant files are being uploaded, DFT as well wannerization based and script too.
You do not have the required permissions to view the files attached to this post.

henrique_miranda
Global Moderator
Global Moderator
Posts: 497
Joined: Mon Nov 04, 2019 12:41 pm
Contact:

Re: Fermi level shift after Wannierization

#4 Post by henrique_miranda » Tue Nov 21, 2023 7:50 am

As I suspected.
Your BAND.dat file has the eigenvalues shifted by the fermi energy reported in the OUTCAR while the wannier90_band.dat is not.
You can check this yourself. The fermi energy is reported in the OUTCAR:
Fermi energy: -0.9803734921

You can either 'unshift' the eigenvalues in your python script or modify the code you used to generate the BAND.dat file.

ahsan_javed
Newbie
Newbie
Posts: 27
Joined: Mon Jun 27, 2022 11:37 am

Re: Fermi level shift after Wannierization

#5 Post by ahsan_javed » Wed Nov 22, 2023 12:35 pm

You are right,

i am using VASPKIT/SUMO for post processing and both having setting enabled: "fermi-level to be zero"

I switch off this setting and there is no shift in wannerization and simple dft band structure.

thanks

Post Reply