EPW Forum

Hi, I believe for the option to work, prefix.eig itself should be sufficient. ksdata.fmt should be generated by the code itself. Something you may want to double check is if you did not use eig_read when doing the Wannierzation (so with epwwrite=.true.), but used it later when you calculate ...

Hi, I think most likely you are seeing the effect intraband absorption due to partial occupancy of the CBM/VBM. Say if I assume your material is not doped, the following is what I think is happening in your case: -In figure 1, the gap seem to be around 1 eV. This is large enough that at 300K, the ...

Hi Ershad, There isn't a too particular reason, but something that I usually do is just to keep them the same as nk and nq for this "initial calculation". But for this calculation really you can just choose any nkf and nqf. What matters is that you see the code finish all the Wannierization and the ...

Hi Ershad, In short, correct, for the "initial" calculation, it does not really matter what your nkf and nqf (they can even be smaller) are as long as your nq and nk corresponds to the electronic (nscf) and phonon (ph.x) calculation you performed. The "restart" calculation is where you evaluate ...

Hi Youzhao, Thanks for the clarification. Interestingly I believe that setting the elecselfen is not supposed to affect the calculated optical spectra. i.e. setting elecselfen does calculate the real and imaginary part of electron-phonon limited electron self energy, but I don't think these are used ...

Hi Youzhao, Thank you for the question. I'm assuming you are talking about the broadening parameter on the denominator of the matrix elements in e.g. Phys. Rev. Lett. 108, 167402? The short answer is, this broadening parameter should not be directly related to the electron self energy, but more as a ...

My first guess would be that the combination of efermi_read and assume_metal might be a problem. I may try to set efermi_read to false first for this metallic system. I don't recall exactly if the other way around works, say you just give it the Fermi level without setting assume_metal, but at the ...

Hi, It would be helpful if you could provide the inputs of your epw1 (wannierization) and epw2 (transport) calculations. It would also be helpful to know the system that you are working on. In my experience, this error mostly happens when there is an inconsistency between the two inputs, and/or ...

Hi, I would be helpful to see the inputs of your EPW calculations and your band structure. Just by looking at the description and the snapshots of the output you attached (DOS=0), my guess would be that your Fermi level is set to a somewhat mid-gap position (so there is no state available for the ...

Hi, First would be helpful if you can share inputs/outputs to see what potential issues there might be. What you mentioned seems possible to be either calculation parameter related, or system related, or both. Regarding the relaxation: -When you say BFGS always fail, do you mean the cell relaxation ...