What do the numbers in Symm_kv stand for?

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Yuan Pang
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Joined: Fri Mar 05, 2021 2:26 pm

What do the numbers in Symm_kv stand for?

Post by Yuan Pang » Mon Oct 18, 2021 1:48 pm

Dear Developers,

We are using ypp to calculate the weights of some specific exciton. The output file lists the k points associate with exciton. But I am confused about the exact meaning of the number "3" and "1" which under the "Symm_kv" tag. As shown in the figure below.

Best regards,
Pang
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School of Physics, Shandong University
Jinan, CHINA

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Daniele Varsano
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Re: What do the numbers in Symm_kv stand for?

Post by Daniele Varsano » Mon Oct 18, 2021 2:00 pm

Dear Hao Zhang,
please sign your post with your affiliation, this is a rule of the forum and you can do once for all filling the signature in your user profile.
The transition are listed in the full BZ, the k points is listed in the IBZ and then expanded with the corresponding operation symmetry of your system.
The symmetry matrix is indicated with an index, in the report file you can find the list of the symmetries together with the index.

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/

Yuan Pang
Posts: 8
Joined: Fri Mar 05, 2021 2:26 pm

Re: What do the numbers in Symm_kv stand for?

Post by Yuan Pang » Mon Oct 18, 2021 3:23 pm

Dear Prof. Daniele

Thank you for your prompt reply!
The symmetry matrix is indicated with an index in the report file, whether the contents in the file correspond to the following statements?
[05.02] Symmetries
==================
DL (S)ymmetries [cc]
[S1] 1.000000 0.000000 0.000000 0.000000 1.000000 0.000000 0.000000 0.000000 1.000000
[S2]-1.000000 0.000000 0.000000 0.000000 -1.000000 0.000000 0.000000 0.000000 1.000000
[S3] 0.000000 1.000000 0.000000 1.000000 0.000000 0.000000 0.000000 0.000000 -1.000000
[S4] 0.000000 -1.000000 0.000000 -1.000000 0.000000 0.000000 0.000000 0.000000 -1.000000
[S5] 1.000000 0.000000 0.000000 0.000000 -1.000000 0.000000 0.000000 0.000000 1.000000
[S6]-1.000000 0.000000 0.000000 0.000000 1.000000 0.000000 0.000000 0.000000 1.000000
[S7] 0.000000 1.000000 0.000000 -1.000000 0.000000 0.000000 0.000000 0.000000 -1.000000
[S8] 0.000000 -1.000000 0.000000 1.000000 0.000000 0.000000 0.000000 0.000000 -1.000000
[SYMs] Time-reversal derived K-space symmetries: 9 16
[SYMs] Spatial inversion 9 is NOT a symmetry
[SYMs] Group table built correctly

Best,
Pang
School of Physics, Shandong University
Jinan, CHINA

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Daniele Varsano
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Re: What do the numbers in Symm_kv stand for?

Post by Daniele Varsano » Mon Oct 18, 2021 3:39 pm

Dear Pang,

yes exactly:

S1-> identity
S2-> inversion in xy plane
and so on,

they are 3x3 matrix written row by row.

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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