Hi Nicki, Sorry I didn't quite follow you: as I understand - correct me if I'm wrong - what you are trying to get is a product of delta functions(?!). They don't have any relations whatsoever with electron-phonon interactions. Am I right? If you don't mind, would you like to tell me why you are tring to get this quantity? The shifting of Fermi energy is done by manually adding 0.05 electrons *within the code*, rather than tot_charge - in the latter way QE calculates forces and phonons with the charged system. But the convergence with respect to smearing is done by visual examination :P - I don't yet know of something that quantifies this criterion :( you are welcome fzm
________________________________ De : pw_forum-bounces at pwscf.org [mailto:pw_forum-bounces at pwscf.org] De la part de nicvok Envoy? : 30 janvier 2014 05:17 ? : pw_forum at pwscf.org Objet : Re: [Pw_forum] electron-phonon coupling, nesting, double-delta Dear Zimin, indeed I try to represent the q-resolved spectral function \alpha^2F(\nu,q) as eq.(3) in your paper, but WITHOUT the square of the interaction strength eq.(2). So what remains is the q-resolved nesting-function. Nevertheless, I found your paper quite interesting. How do you technically achieved the rigid-band shift? Did you add the additional 0.05 electrons by setting tot_charge = 0.0500000? How do you control the convergence of the electron-phonon parameter \Lambda or the Eliashberg function with respect to the smearing of the double-delta integral if you are so close to the bandedge? I would really appreciate your answers and ideas. thanks a lot Nicki ------------------------------------------------------------- Nicki Frank Hinsche, Dr. rer. nat. Institute of physics - Theoretical physics, Martin-Luther-University Halle-Wittenberg, Von-Seckendorff-Platz 1, Room 1.07 D-06120 Halle/Saale, Germany Tel.: ++49 345 5525460 ------------------------------------------------------------- To: "PWSCF Forum" <pw_forum at pwscf.org> Message-ID: <FB5F7460B39A4740A5EA3234900DA8E11DA527 at WPEXCV106.hydroqc.hydro.qc.ca> Content-Type: text/plain; charset="iso-8859-1" Hi Nicki, Let me know if this is what you are trying to do: http://prb.aps.org/abstract/PRB/v88/i18/e184302 fzm -----Message d'origine----- De : pw_forum-bounces at pwscf.org [mailto:pw_forum-bounces at pwscf.org] De la part de nicvok Envoy? : 27 janvier 2014 13:28 ? : pw_forum at pwscf.org Objet : [Pw_forum] electron-phonon coupling, nesting, double-delta Dear all, I am trying to extract the nesting function/double delta X(q,\nu) (sim. to eq.(22)/(A1) in Wierzbowska et al. http://arxiv.org/abs/cond-mat/0504077) out of QE503. I would like to have it in the same way as the phonon linewidth g(q,\nu) (gamma(i,n) in matdyn.f90). A starting point would be gf(mu,nu,isig) in elphon.f90 and/or phase_space in elphsum_simple in elphon.f90, which should both represent the double delta by using gaussians. However, I am right now puzzled and wondering where I have to search/work for an direct output of the nesting function for arbitrary q? I would appreciate any hint. Nicki -------------- next part -------------- An HTML attachment was scrubbed... URL: http://pwscf.org/pipermail/pw_forum/attachments/20140130/1d4ad8fe/attachment.html
