[Pw_forum] electron-phonon coefficient

Eyvaz Isaev eyvaz_isaev at yahoo.com
Mon Apr 13 00:08:02 CEST 2009


Dear Sanjeev,

Please have look at elph.tar.gz attached. I think it contains almost all information everybody needs to calculate electron-phonon interaction (run_example file is taken from /example07 directory).
I have included revised elphon.f90 and lambda.f90. 

The first one is useful if you do not have elph-files (like elph.qx.qy.qz) using QE distribution, then replace standard (from QE distribution) elphon.f90 and recompile ph.x.

The second one has one more useful output as T_c using the Allen-Dynes formula. I would suggest official lambda.f90 might be replaced by this one.

As concerns Raman and IR spectra: If you are interested in IR and Raman active modes see phonon output file for Gamma point. If you need Raman and IR cross sections see dynmat.f90 (and then use dynmat.x). If you need Raman tensors then setup lraman=.true. in phonon input file. As you need Born effective charges Z* you also should specfy epsil=.true. keyword. 

See /Doc/INPUT_PH.txt and header part of /PH/dynmat.f90 file.

Bests
Eyvaz.

-------------------------------------------------------------------

Prof. Eyvaz Isaev, 

Theoretical Physics Department, Moscow State Institute of Steel & Alloys, Russia, 

Department of Physics, Chemistry, and Biology (IFM), Linkoping University, Sweden 

Condensed Matter Theory Group, Uppsala University, Sweden 

Eyvaz.Isaev at fysik.uu.se, isaev at ifm.liu.se, eyvaz_isaev at yahoo.com

--- On Sun, 4/12/09, Sanjeev K. Gupta <sanjeev0302 at rediffmail.com> wrote:
From: Sanjeev K. Gupta <sanjeev0302 at rediffmail.com>
Subject: electron-phonon coefficient
To: "eyvaz_isaev" <eyvaz_isaev at yahoo.com>
Date: Sunday, April 12, 2009, 7:51 AM


Respected Sir,



1. I want to calculate the electron-phonon coefficient "lamda" and the function "square of alpha" F(w) plot, how i do?



2. I also want to calculate IR spectra and Raman spectra? 



Thanks in advance!!



Sanjeev Gupta 





S. K. Gupta


PhD Candidate,


Dept. of Physics,


Bhavnagar University.


Bhavnagar, 364 002., Gujarat.








      
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