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How to obtain absorption coefficient

Posted: Wed Jun 30, 2021 12:21 pm
by Zafer Kandemir
Dear Developers,

I study 2D systems. First, I calculate the GW then BSE. I obtain o-md.alpha_q1_diago_bse, o-md.eel_q1_diago_bse and o-md.eps_q1_diago_bse files. How to obtain absorption coefficient and what is the unit?

Best regards.
Zafer

I added the Yambo input file.

Re: How to obtain absorption coefficient

Posted: Wed Jun 30, 2021 12:33 pm
by Daniele Varsano
Dear Zafer,
depending on what you want to calculate you can do it from the real and image part of eps and/or alpha.
eps has not unit by definition. alpha it is given in atomic unit so it is [au]^3

Best,
Daniele

Re: How to obtain absorption coefficient

Posted: Wed Jun 30, 2021 12:50 pm
by Zafer Kandemir
Dear Daniele,

Thank you for replying. I obtained the absorption coefficient I(w) by using eps1 and eps2 with the attached equation (J. Mater. Chem. A, 2013, 1, 2231–2237) . Am I doing it right?

Zafer

Re: How to obtain absorption coefficient

Posted: Wed Jun 30, 2021 1:20 pm
by Daniele Varsano
Dear Zafer,
I do not know exactly wha you want to calculate, from eps1 and eps2 you can extract refractive indexes, extinction coefficients etc.
You can have a look to this chapter by M. S. Dresselhaus

http://web.mit.edu/course/6/6.732/www/6.732-pt2.pdf

In particular Section 1.3

Best,
Daniele