Yambo Community Forum

Please excuse me for crossposting (see: viewtopic.php?t=2328).

Hello,

I would like to know how you can compute the static dielectric function eps^{-1} (q, G,G') from the ndb.em1s databases.
I found in a yambopy script that the following quantity is stored in the ndb.em1s files: sqrt(v(q+G)) chi(G,G') sqrt(v(q + G')).
To isolate the epsilon, I have to compute eps^{-1} (q, G,G') = delta_{G,G'} + v(q+G) chi(G,G') for G .ne. G'

But in order to do so, I need to exactly know how you build your Coulomb interaction, especially in the limits of q -> 0 or G -> 0 or both.

Thanks for your help.

Edit:
I am additionally using the RIM as well as the truncated Coulomb potential within a box z geometry to properly treat the 2D systems of study.
Thus, I also have the ndb.RIM and ndb.cutoff that I probably need to correctly construct v(q, G).

Best,
Franz Fischer

Dear Franz

please have a look to yambopy, it contains python libraries to read the yambo databases

https://github.com/yambo-code/yambopy

in particular the file:

yambopy/dbs/em1sdb.py

best
Claudio