Smearing problem in qp spectral function!

Post here any question you encounter when running the scripts of the yambo-py suite. Post here problem strictly to the python interface as problem coming from the yambo runs should go in the appropriate subforum.

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sitangshu
Posts: 175
Joined: Thu Jan 05, 2017 8:08 am

Smearing problem in qp spectral function!

Post by sitangshu » Tue Feb 07, 2017 7:42 am

Dear Sir,

While doing a calculation with Si bulk, I made "occupation" to be a "fixed" in my ground state calculation. I understood that this actually removes the "Warning: Metallic System" note that comes after the yambo calculation. However, when I progress further with this for the qp electron-phonon calculations using elph_qp, the non-zero temperature suffers NAN error.
This however does not come when I change "fixed" to "guassian" with a suitable "degauss"!.
Where I am doing wrong, if you can tell me please...

With regards

Sitangshu
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Sitangshu Bhattacharya
Indian Institute of Information Technology-Allahabad
India
Web-page: http://profile.iiita.ac.in/sitangshu/
Institute: http://www.iiita.ac.in/

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amolina
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Re: Smearing problem in qp spectral function!

Post by amolina » Tue Feb 07, 2017 9:32 am

Dear Sitangshu,
I don't understand very well where it can be the problem. Can you attach a tar file with the QE and yambo input files?
Alejandro Molina-Sánchez
Institute of Materials Science (ICMUV)
University of Valencia, Spain

sitangshu
Posts: 175
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Re: Smearing problem in qp spectral function!

Post by sitangshu » Tue Feb 07, 2017 9:52 am

Dear Alejandro,

Here are the files attached...

Regards,
Sitangshu
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Sitangshu Bhattacharya
Indian Institute of Information Technology-Allahabad
India
Web-page: http://profile.iiita.ac.in/sitangshu/
Institute: http://www.iiita.ac.in/

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amolina
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Re: Smearing problem in qp spectral function!

Post by amolina » Tue Feb 07, 2017 10:09 am

Dear Sitangshu,
what I see from the inputs is the runlevel for a GW calculation. I don't think you can set the Bose Temperature in this calculation if you don't have the electron-phonon matrix elements.
Alejandro.
Alejandro Molina-Sánchez
Institute of Materials Science (ICMUV)
University of Valencia, Spain

sitangshu
Posts: 175
Joined: Thu Jan 05, 2017 8:08 am

Re: Smearing problem in qp spectral function!

Post by sitangshu » Tue Feb 07, 2017 11:16 am

Dear Alejandro,

I think I am not understanding.... Please excuse me. Please tell me where I am wrong..
1. I understand that the current version of Yambo doesn't include Matsubara analysis.
2. The inclusion of temperature comes from electron-phonon interaction.

Should I be including then the Bose temperature in the file elph_pw_si itself or in elph_qp_si? It appears to me that there should be something to counterbalance the "smearing" part in DFT analysis.
I am actually following the electron-phonon tutorial in the yambopy documentation.

With regards,
Sitangshu
Sitangshu Bhattacharya
Indian Institute of Information Technology-Allahabad
India
Web-page: http://profile.iiita.ac.in/sitangshu/
Institute: http://www.iiita.ac.in/

sitangshu
Posts: 175
Joined: Thu Jan 05, 2017 8:08 am

Re: Smearing problem in qp spectral function!

Post by sitangshu » Tue Feb 07, 2017 1:44 pm

Dear Alejandro,

The smearing problem is now solved !!

With regards,

Sitangshu
Sitangshu Bhattacharya
Indian Institute of Information Technology-Allahabad
India
Web-page: http://profile.iiita.ac.in/sitangshu/
Institute: http://www.iiita.ac.in/

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