Different energy range of band structure in EPW and Quantum espresso

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mirshowkat07
Posts: 23
Joined: Tue Aug 21, 2018 11:24 am
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Different energy range of band structure in EPW and Quantum espresso

Post by mirshowkat07 »

Dear EPW users

The energy range of EPW band structure and QE is not the same as shown in the attached Figure.
One can see from the Figure that the x-axis for QE bands is from 0 to 1.56 eV, while for EPW bands, it is 0 to 1.8 eV.
Due to this, the EPW bands are not overlapping with the QE band structure.
This type of problem does not occur with phonon band structure which looks fine.
I did many calculations by changing the frozen energy window and which wannier bands to plot, etc., but I am getting similar results every time.

Could anybody help me how to get EPW bands similar to QE?

Best Regards
Showkat
HRI, Allahabad, India.
Attachments
Bands.png
Bands.png (22.81 KiB) Viewed 53 times

hpaudya1
Posts: 125
Joined: Tue Mar 21, 2017 7:11 pm
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Re: Different energy range of band structure in EPW and Quantum espresso

Post by hpaudya1 »

Hi Showkat,

The x-axis is not the energy axis, it is the wavevector (high symmetry direction).

Could you double-check the co-ordinate of your high-symmetry points in QE band calculation and EPW? It would be to help you if you could provide your input files.

Best,
Hari Paudyal

mirshowkat07
Posts: 23
Joined: Tue Aug 21, 2018 11:24 am
Affiliation:

Re: Different energy range of band structure in EPW and Quantum espresso

Post by mirshowkat07 »

Dear Hari Paudyal

Thank you for correcting me; the x-axis is the wavevector, true.
The number of high-symmetry k-points used in EPW calculations is taken from QE bands.out file.
The total number of K-points was the same in both the calculations.
The files are attached herewith.
Thank you for your mail


best regards
SHowkat
Attachments
PtS2.zip
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hpaudya1
Posts: 125
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Re: Different energy range of band structure in EPW and Quantum espresso

Post by hpaudya1 »

Hi SHowkat,

Could you please use crystal coordinates instead 2pi/alat in the EPW calculation?

Best,
Hari

mirshowkat07
Posts: 23
Joined: Tue Aug 21, 2018 11:24 am
Affiliation:

Re: Different energy range of band structure in EPW and Quantum espresso

Post by mirshowkat07 »

Dear Hari Paudyal

So nice of you to help me to solve my problem.
The bands are now precisely overlapping by using the crystal coordinates.
Thanks a ton.


best regards
Showkat

hpaudya1
Posts: 125
Joined: Tue Mar 21, 2017 7:11 pm
Affiliation:

Re: Different energy range of band structure in EPW and Quantum espresso

Post by hpaudya1 »

Hi Showkat,

Great to know that your problem is solved. There might be some issue with the 2pi/alat coordinate in the implementation, I will have a look at it and update if required.

Happy EPWing,
Hari

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