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BSE code does not support metals?

Posted: Sat Apr 02, 2016 1:00 am
by hammouri
Hello all,
I have problem running BSE, I have an interface between two insulators SrTiO3 and LaAlO3. but I got an error saying:
BSE code does not support metals
I do not know why it assumed metal and it is an insulator?

Best,
MH
ASU

Re: BSE code does not support metals?

Posted: Sat Apr 02, 2016 7:52 pm
by hammouri
Any answer.

Re: BSE code does not support metals?

Posted: Tue Apr 05, 2016 12:18 pm
by gmatteo
Which value of occopt are you using?
Have you looked at the occupation factors obtained by Abinit at the end of the GS calculation?

Note that in metallic systems, excitonic effects are strongly dumped and one can obtain
reasonably good results by simply using the Random-Phase approximation.

The BSE code does not support metals because there are additional terms in the BSE HAmiltonian
that are not included.

Re: BSE code does not support metals?

Posted: Tue Apr 12, 2016 6:09 am
by hammouri
Thank you gmatteo for your reply. As I mentioned the system I working on are insulators with large gap. I'm using the default value of occupy, see the input files.

Re: BSE code does not support metals?

Posted: Tue Apr 12, 2016 7:52 am
by hammouri
I just tried the occopt=7 but not working !

Re: BSE code does not support metals?

Posted: Thu May 12, 2016 10:43 am
by ygillet
Dear hammouri,

Occopt = 7 will allow you to have metallic occupations, but it won't help to run BSE...

Could you check the occupation numbers of your calculations ?
If you have metallic occupations or bands with different occupations, you won't be able to run BSE.
If you try to simulate a wide band gap insulator and you get metallic occupations, then you should worry first about your band structure and check it's correct before going to MBPT and BSE.

Regards,

Yannick