Question about the Symm. in .exc_weights file

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lyzhao
Posts: 8
Joined: Tue May 31, 2016 8:02 am

Question about the Symm. in .exc_weights file

Post by lyzhao » Sun May 22, 2022 1:09 am

Dear all,
To analysis the exciton, I generate the file *.exc_weights_at_1 by following the tourtial.
In the .exc_weights_at_1 file, we see that (note that I reduce the threshold of weight output to 0.01)
# Band_V Band_C K ibz Symm. Weight Energy
#
8.000 9.000 90.00 4.000 0.1288E-1 4.717
8.000 9.000 90.00 6.000 0.1288E-1 4.717
8.000 9.000 90.00 2.000 0.1287E-1 4.717
8.000 9.000 90.00 1.000 0.1287E-1 4.717
....
Now, I have two questions:
1. There are multiple Symm. for the same ibzK and Band_V_C pair, why? Do they mean the unfold of ibz?
2. Where can I find the symm. symbol (i.e., Ag, Au, etc) of these Symm. number? Which file?
Youzhao Lan
Department of Chemistry,College of Chemistry and Life Sciences,
Zhejiang Normal University,
Jinhua, Zhejiang,
321004, China.
HomePage: http://blog.sciencenet.cn/u/lyzhao

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Daniele Varsano
Posts: 3354
Joined: Tue Mar 17, 2009 2:23 pm
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Re: Question about the Symm. in .exc_weights file

Post by Daniele Varsano » Mon May 23, 2022 7:50 am

Dear Youzhao,

yes the BSE is solved in the full BZ. Next, a transition in the expanded BZ is indicated as a k point in the IBZ plus a symmetry indicated by an index.
The symmetries matrices corresponding to the index are indicated in the report files in the section:

Code: Select all

 [02.02] Symmetries
  ==================
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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