Yambo Community Forum

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

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

Dear Daniele,

many thanks, this is very helpful.

Best regards,

Antonios