Yambo Community Forum

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.

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

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.

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