GW QPband

Concerns issues with computing quasiparticle corrections to the DFT eigenvalues - i.e., the self-energy within the GW approximation (-g n), or considering the Hartree-Fock exchange only (-x)

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WEIW
Posts: 37
Joined: Fri Nov 24, 2017 9:48 am

GW QPband

Post by WEIW » Wed Dec 20, 2023 10:04 am

Dear all,

There was no error when I performed gw calculation, but I wondered why the corrected energy band would appear in a relatively "chaotic" state. What are the reasons for this?

I have attach the relevant results below. Figure 1/2 shows the band structure calculated with/without GW correction respectively.

Thanks in advance.
Best,
Liu
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Dr. LIU Hongling
School of Physics, Shandong University
Jinan, CHINA

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claudio
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Re: GW QPband

Post by claudio » Fri Dec 22, 2023 10:26 am

Dear Liu

probably it is not an error of the GW calculations but a problem in the interpolation.
When two bands cross each other in the GW, the interpolation could fail, because it is not able
to recognize the crossing.
My advice is to plot directly the points that you obtain from the GW without interpolation,
you should be able to recognize the bands and their path without strange behaviours.

best
Claudio
Claudio Attaccalite
[CNRS/ Aix-Marseille Université/ CINaM laborarory / TSN department
Campus de Luminy – Case 913
13288 MARSEILLE Cedex 09
web site: http://www.attaccalite.com

WEIW
Posts: 37
Joined: Fri Nov 24, 2017 9:48 am

Re: GW QPband

Post by WEIW » Tue May 21, 2024 2:02 pm

Dear Claudio,

Thanks for your advise!

I'm not sure how to implement "plot directly without interpolation". I would appreciate it if you could explain it in detail. Thank you very much!

Best,
Liu
Dr. LIU Hongling
School of Physics, Shandong University
Jinan, CHINA

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Daniele Varsano
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Re: GW QPband

Post by Daniele Varsano » Tue May 21, 2024 6:06 pm

Dear Liu,

you can plot the calculated QP energy that are found both in the o.qp* file and in the report file.

Best,
Daniele
Dr. Daniele Varsano
S3-CNR Institute of Nanoscience and MaX Center, Italy
MaX - Materials design at the Exascale
http://www.nano.cnr.it
http://www.max-centre.eu/

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