Wannier interpolated electronic band structure

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sridhu88
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Joined: Tue Jul 12, 2016 3:51 pm
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Wannier interpolated electronic band structure

Post by sridhu88 »

Hello,
I'm new to EPW, so apologies if the question is too simple. I want to plot the Wannier interpolated electronic band structure and compare with the band structure obtained directly from DFT. So I set band_plot = .true. when running the calculation. I find a file called "phband.freq" which I believe is the phonon band structure after Wannier interpolation. However, I don't find a similar file for the electronic band structure.

I calculated the imaginary part of electron-self energies along a specific path in BZ and the file linewidth.elself seems to contain a column of electron energies. Is this the interpolated band structure that I need to compare with DFT?

Thanks,
Sridhar
Argonne National Lab

sponce
Site Admin
Posts: 616
Joined: Wed Jan 13, 2016 7:25 pm
Affiliation: EPFL

Re: Wannier interpolated electronic band structure

Post by sponce »

Dear Sridhar,

With band_plot = .true. you can provide a k-path or a q-path (using filkf or filqf) that will give you the electron or phonon bandstructure.

In addition, if you want the electronic bandstructure produced directly by Wannier you can also use wdata flag and the normal Wannier input variables:

Code: Select all

  wdata(1) = 'bands_plot = .true.'
  wdata(2) = 'begin kpoint_path'
  wdata(3) = 'G  0.0  0.0   0.0 X  0.5  0.5   0.0'
  wdata(4) = 'X  0.5  0.5   0.0 X  1.0  0.5   0.5'
  ....
  wdata(8) = 'X  0.5  0.5   0.0 W  0.75 0.5   0.25'
  wdata(9) = 'W  0.75 0.5   0.25 L 0.5  0.0   0.0'
  wdata(10) = 'end kpoint_path'
  wdata(11) = 'bands_plot_format = gnuplot'


This will produce a XXX_band.gnu file.

Best,

Samuel
Prof. Samuel Poncé
Chercheur qualifié F.R.S.-FNRS / Professeur UCLouvain
Institute of Condensed Matter and Nanosciences
UCLouvain, Belgium
Web: https://www.samuelponce.com

sridhu88
Posts: 14
Joined: Tue Jul 12, 2016 3:51 pm
Affiliation:

Re: Wannier interpolated electronic band structure

Post by sridhu88 »

Dear Samuel,

Thank you for your response. I actually missed that a file called "band.eig" gets created which I think contains the band structure. And yeah the method you mentioned on directly obtaining a gnu plot file from Wannier90 is even better.

Thanks!
Sridhar

sponce
Site Admin
Posts: 616
Joined: Wed Jan 13, 2016 7:25 pm
Affiliation: EPFL

Re: Wannier interpolated electronic band structure

Post by sponce »

Dear Sridhar,

Yes that's the file !

And no, its not better.

What you want is correct Wannier interpolation at the level of EPW (becasue this is what is used during the EPW run). Therefore you should check band.eig and phband.freq.

The XXX_band.gnu directly from Wannier is only an additional checking in case there is an issue (to see weather the problem comes from Wannier or EPW).

Best,

Samuel
Prof. Samuel Poncé
Chercheur qualifié F.R.S.-FNRS / Professeur UCLouvain
Institute of Condensed Matter and Nanosciences
UCLouvain, Belgium
Web: https://www.samuelponce.com

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