How to plot the band structure of GW using o.qp file

Deals with issues related to computation of optical spectra, in RPA (-o c) or by solving the Bethe-Salpeter equation (-o b). Includes local field effects, excitons, etc.

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lamia
Posts: 18
Joined: Mon Dec 05, 2016 5:09 pm

How to plot the band structure of GW using o.qp file

Post by lamia » Tue Oct 30, 2018 7:40 am

Dear YAMBO developer,
I calculated a simple GW calculation with yambo 4.0.4 (or 4.1.1) following command line for GWA
../yambo -g n -p p -k hartree . I get a file o.qp with:

# K-point Band Eo E-Eo Sc|Eo

but I don't know how to get the band gap value and how to plot the band structure of the system?
Also, what's the information can I get it from it.

Best,
Lamia
Taouil Lamia
University of Mohammed V
Faculty of science - Rabat
Morocco

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Daniele Varsano
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Joined: Tue Mar 17, 2009 2:23 pm
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Re: How to plot the band structure of GW using o.qp file

Post by Daniele Varsano » Tue Oct 30, 2018 9:09 am

Dear Lamia,
but I don't know how to get the band gap value and how to plot the band structure of the system?
The band gap is contained in the o.qp as you have the GW correction, provided that you calculated the GW correction for the band and K point
where the gap appear.

In order to have the band structure through a path connecting high symmetry point you need to interpolate the QP energies: this is explained for instance
at the end of this GW tutorial:
http://www.yambo-code.org/wiki/index.ph ... rial:_h-BN
Also, what's the information can I get it from it.
IN the o.qp essentially you have the output of your calculation, GW correction, exchange self energy contribution, correlation self energy contribution etc..
What information you can get from a GW calculation, I invite you to look at some textbook or review on the topic.
Here you can find links to lecture notes, reviews, book chapters etc.:
http://www.yambo-code.org/theory/lectures.php


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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