bare Coulomb matrix

Run-time issues concerning Yambo that are not covered in the above forums.

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alvert92
Posts: 2
Joined: Fri Sep 28, 2018 11:49 am

bare Coulomb matrix

Post by alvert92 » Thu Oct 31, 2019 3:32 pm

Dear Yambo community,

I was wondering whether there is a straightforward way of printing the matrix elements <cvk|v|c'v'k'> of the bare Coulomb interaction in Yambo. I found this post: viewtopic.php?f=10&t=1399 where printing the screened Coulomb matrix W is discussed, by modifying K.F . Therefore, I assume it must be possible to print out the bare Coulomb matrix as well. Unfortunately I was not able to figure out how to do it by looking through the K.F script. Could you please advise? Many thanks in advance.

Antonios
Antonios Alvertis

Ph.D. Candidate
Cavendish Laboratory
University of Cambridge

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Daniele Varsano
Posts: 2723
Joined: Tue Mar 17, 2009 2:23 pm
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Re: bare Coulomb matrix

Post by Daniele Varsano » Thu Oct 31, 2019 3:43 pm

Dear Antonios,
in the post you mention H_c are the screened potential matrix elements while H_x are the bare Coulomb matrix elements. Note that in the BSE the bare coulomb potential enters without the head (G=0) component.

Another way to extract them without changing the source could be to perform a BSE calculation including the exchange part only in the kernel and then read the netcdf databases with an external script (e.g. python).

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/

alvert92
Posts: 2
Joined: Fri Sep 28, 2018 11:49 am

Re: bare Coulomb matrix

Post by alvert92 » Thu Oct 31, 2019 3:53 pm

Dear Daniele,

many thanks, this is very helpful.

Best regards,

Antonios
Antonios Alvertis

Ph.D. Candidate
Cavendish Laboratory
University of Cambridge

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