Composition of RPA absorption spectrum - ypp

[vamshi.katukuri]

Dear all,

I am interested in analysing the optical spectrum at the RPA level. Basically I would like to know the contributions of different band transitions that are responsible for the observed peaks in optical absorption spectrum. I know that one can do that for an exciton using ypp. Is it possible to do the same at the RPA level?
Or do we have to write our own program?

Regards
Vamshi
PostDoc
Institute of Physics, EPF Lausanne

[Daniele Varsano]

Dear Vamshi,
you can do that by solving RPA equation in transition space, as in G space this information it is not available.
Using the BSE input and setting BSKmod=Hartree.
This is in fact the RPA in transition space. In order to be exactly equivalent to the one calculated in G space you need to include also the coupling part.
Next proceed with ypp exactly as for the BSE calculation.

Best,

Daniele

[vamshi.katukuri]

Dear Daniele,

Thank you for your quick reply. I will try to do that.

Regards
Vamshi