eps0/Im[4]

[WEI Wei]

Dear All,

Does the fourth column in the file of "o.eps_q1_haydock_bse" include the so-called local field effects?
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# E/ev[1] eps /Im[2] eps /Re[3] eps0/Im[4] eps0/Re[5] eps`/Im[6] eps`/Re[7]

0.000 0.6630E-3 1.413 0.4392E-3 1.337 0.6630E-3 1.413
0.2002E-1 0.6708E-3 1.414 0.4438E-3 1.337 0.6708E-3 1.414
0.4004E-1 0.6786E-3 1.415 0.4484E-3 1.338 0.6786E-3 1.415
0.6006E-1 0.6866E-3 1.417 0.4531E-3 1.339 0.6866E-3 1.417
0.8008E-1 0.6946E-3 1.418 0.4578E-3 1.340 0.6946E-3 1.418
... ...
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If not, how can I obtain a GW absorption spectrum including the local field effects? Can I use the "KfnQPdb= "E < ./SAVE/ndb.QP"" in the "yambo -o c -V qp" calculation?

Thank you very much!

[claudio]

Dear WEI Wei

you can obtain a GW absorption spectrum including the local field effects doing

yambo -o c -V qp

and then setting

XfnQPdb="E < ./SAVE/ndb.QP"

Cla

[WEI Wei]

Dear Claudio,

Thank you very much for your reply!
So, the difference between eps0/Im[4] from o.eps_q1_haydock_bse and the yambo -o c -V qp is that the former does NOT include the LFE?
If I use yambo -o c -V qp, how to set the variables like XfnQP_W, XfnQP_Z?

Thanks!

[myrta gruning]

Hallo

The eps0 is the independent particle one, so yes no many-body effects are there (e.g. no LF or excitonic effects)

Best
m

[Daniele Varsano]

If you want to include Qp energy corrections, just set the XfnQP_E variable.
Cheers,
Daniele

[WEI Wei]

Dear Daniele & Myrta,

Thank you very much!
I know I can do it by setting the XfnQP_E, but it is OK for a system with an indirect band gap?
In addition, I want to know that can I use the "XfnQPdb="E < ./SAVE/ndb.QP"" in the input file without setting the other relative variables?

Thanks!

[Daniele Varsano]

Dear Wei,

I know I can do it by setting the XfnQP_E, but it is OK for a system with an indirect band gap?

Here you are reading the QP corrections that you should have calculated in advance. Using the variable with that
syntax it is not a scissor!

In addition, I want to know that can I use the "XfnQPdb="E < ./SAVE/ndb.QP"" in the input file without setting the other relative variables?

Yes you can, if you are interested in the energy corrections, this is the variable to use.

Cheers,
Daniele

[WEI Wei]

Dear Daniele,

OK, I see.
Thank you so much for your patience!