I performed a Handson tutorial of "Ponce" on electronphonon matrix elements. And I have a couple of questions please. I am a new user
1 I obtained the interpolated band structure with EPW (BS_pw_epw.png) but still I don't understand what is different about it compared to the one obtained with pw.x. Maybe it should be the last band up and down? I thought after doing epw.x calculation, I will clearly see the influence of the electronphonon (eph) coupling on the band structure of lead.
2I noticed that the phonon frequencies (disp_pw_epw.png) calculated with both pw.x and epw.x perfectly coincide and I don't understand why?
3After epw3.in where I am to find the phonon linewidths, the imaginary part of the phonon selfenergy and the electronphonon strength associated to phonon modes and wave vectors, it is said that the phononself energy are respectively saved in the files linewidth.phself.XXXK and lambda.phself.XXXK. But, when I open the first file (linewidth.phself.0.075K) I only see the Phonon frequency and phonon linewidth. In the second file ( lambda.phself.0.075K) it is written "Lambda phonon selfenergy". I am a bit confused because in the first file, I was to find the imaginary part of the eph selfenergy and in the second file the eph coupling strength. So please, how should I exactly identify each of the three elements?
4I was expecting that after taking into consideration the eph coupling and performing the epw.x calculation, I will observe a change in the band structure (like a change in the band gap for example) but I am really unable to point out the effect of the eph coupling after these calculations.
I'm looking forward to hearing from you.
Perform electronPhonon coupling
Moderator: hlee
Perform electronPhonon coupling
 Attachments

 Phonon frequency with pw.x and epw.x
 disp_pw_epw.png (39.13 KiB) Viewed 136 times

 Band structure with pw.x and epw.x
 BS_pw_epw.png (48.28 KiB) Viewed 136 times
Re: Perform electronPhonon coupling
Hi Lavoisier,
1 and 2. The interpolated band/phonon looks good. In the band structure, the top and bottom bands with PW are not included in the wannierization, so you do not see in the EPW calculation.
3. I think, you need to read EPW documentation in more details.
4. No, EPW does not help improve the band gap and etc.
Happy EPWing,
Hari
1 and 2. The interpolated band/phonon looks good. In the band structure, the top and bottom bands with PW are not included in the wannierization, so you do not see in the EPW calculation.
3. I think, you need to read EPW documentation in more details.
4. No, EPW does not help improve the band gap and etc.
Happy EPWing,
Hari