How to construct epsilon^{-1}(q, G, G') from ndb.em1s

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Franz Fischer
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Joined: Wed Jul 20, 2022 9:36 am

How to construct epsilon^{-1}(q, G, G') from ndb.em1s

Post by Franz Fischer » Wed Nov 23, 2022 11:21 am

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
Franz Fischer
PhD student / IMPRS-UFAST fellow
Institute of Physical Chemistry
University of Hamburg

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claudio
Posts: 448
Joined: Tue Mar 31, 2009 11:33 pm
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Re: How to construct epsilon^{-1}(q, G, G') from ndb.em1s

Post by claudio » Fri Dec 09, 2022 5:39 pm

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
Claudio Attaccalite
[CNRS/ Aix-Marseille Université/ CINaM laborarory / TSN department
Campus de Luminy – Case 913
13288 MARSEILLE Cedex 09
web site: http://www.attaccalite.com

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