Question about the Symm. in .exc_weights file

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lyzhao
Posts: 40
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
College of Chemistry and Materials Science,
Zhejiang Normal University,
Jinhua, Zhejiang, China.
HomePage: http://blog.sciencenet.cn/u/lyzhao

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Daniele Varsano
Posts: 3773
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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