Databases in examples of Electron-Phonon effects in Si?

Run-time issues concerning Yambo that are not covered in the above forums.

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Dean
Posts: 103
Joined: Thu Oct 10, 2019 7:03 am

Databases in examples of Electron-Phonon effects in Si?

Post by Dean » Tue Oct 22, 2019 8:13 am

Dear all,
I am doing the example of Electron-Phonon effects in seminconductors: the band-gap and absorption spectrum of Silicon and Diamond.
After downloading the YAMBO CORE DATABASES and REFERENCE files, I found no folders of DFT/ DFT_commons/ DFT_dVscf/ DFT_el-ph/...
And the procedure to get the el-ph databases ndb.elph_gkkp_fragment* is not described in webste http://www.yambo-code.org/tutorials/Ele ... ndex.php#E
So, how to get the el-ph databases ndb.elph_gkkp_fragment* based on QE?
Thanks in advances.
Dr. Yimin Ding
Soochow University, China.

elena.cannuccia
Posts: 23
Joined: Tue Oct 11, 2016 10:58 am

Re: Databases in examples of Electron-Phonon effects in Si?

Post by elena.cannuccia » Wed Oct 23, 2019 9:39 am

Dear Dr. Yimin Ding,

Do you have the the s.dbph_000* databases plus the SAVE directory with ns.* files inside ?

If yes,
1) "yambo_ph -i -V kpt -F init.in" then edit the input file uncommenting "MinusQ".
2) "yambo_ph -F init.in"
3) "ypp_ph -g"
4) "ypp_ph"

Let me know.

Elena

Dean
Posts: 103
Joined: Thu Oct 10, 2019 7:03 am

Re: Databases in examples of Electron-Phonon effects in Si?

Post by Dean » Thu Oct 24, 2019 4:13 am

Dear Elena,
Thanks for your reply.
I do not have the the s.dbph_000* databases plus the SAVE directory with ns.* files inside.
Actually, I do not know how to get electron-phonon databases imported from QE. And the procedure to get the el-ph databases is not presented in the tutorial.
So, can you give me some help? Thanks a lot.
Dr. Yimin Ding
Soochow University, China.

elena.cannuccia
Posts: 23
Joined: Tue Oct 11, 2016 10:58 am

Re: Databases in examples of Electron-Phonon effects in Si?

Post by elena.cannuccia » Fri Oct 25, 2019 1:27 pm

Dear Yimin,

I suggest to use Quantum espresso qe-6.1.0.

1) a scf calculation choosing the k grid and setting force_symmorphic=.true.
2) a dVscf calculation, meaning a phonon calculation setting the flag electron_phonon = 'dvscf', and a q grid equivalent to the k grid you used before.
3) a nscf calculation, setting the number of bands nbnd = ... , force_symmorphic=.true. and the same q grid as before
4) an elph calculation setting electron_phonon = 'yambo', and the q grid (the same as before).

once the calculation is completed, you can plug into nscf/*save and type "p2y" . At this point you follow the procedure I wrote you in my first reply.

Elena

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