EPW Forum

Hi Animesh, Your understanding is mostly correct, but keep in mind that the header of ephmat files contains two integers. These integers ensure the files are read correctly, even when a different number of pools is used. https://gitlab.com/QEF/q-e/-/blob/qe-7.4.1/EPW/src/io/io_supercond.f90#L2288 ...

Dear Li, You might want to review the input parameters used in ph.x for calculating the electron-phonon coupling. When performing these calculations with ph.x, did you follow the steps outlined in Section 4.5 of the user guide (https://gitlab.com/QEF/q-e/-/blob/develop/PHonon/Doc/user_guide.pdf ...

Dear Li, Thank you for sharing the spatial decays. They appear to be well localized with respect to the lattice vectors. While it might be possible to slightly improve the spatial localization by increasing the number of Wannier orbitals, it is unlikely that this is the main cause of the discrepancy ...

Dear Li, I initially misunderstood that you were using EPW for Pb, but you are actually working with TaNbHfZr, correct? To rule out the possibility that the issue originates from the orbitals, it would be prudent to re-examine them, especially when dealing with a new system in EPW. Have you plotted ...

Dear Li, Even if the Wannier bands closely reproduce the DFT bands, the Wannier orbitals may not be ideal for EPW. To effectively interpolate the electron-phonon interaction, the Wannier orbitals must be spatially localized. I strongly recommend repeating the calculations using the s and p orbitals ...

Dear Li, I guess your calculations are collinear and do not account for spin-orbit interaction, which may lead to an overestimation of the Allen-Dynes Tc compared to its expected converged value. With this in mind, I have a few concerns: 1. If the target system is truly fcc Pb, the p orbitals of Pb ...

Dear Jianguo, To render the Fermi surface correctly, it is essential to obtain energy values at all points on the 3D grid (kx, ky, kz). Without this, the isosurface cannot be rendered smoothly. The same requirement applies to the superconducting gap function to be visualized on the Fermi surface—it m ...

Dear Simone, In addition to Shashi's question, please check again that efermi_read has been correctly set. In particular, in your input file used for calculations where the DOS was not computed correctly, was efermi_read set to false? The default value is false, so it will be false if not specified ...

Dear Jarin, The Padé approximation is a relatively robust method, but it can fail to calculate Padé coefficients when using many Matsubara frequencies. This is particularly true because the gap function at higher Matsubara frequencies often contains numerical noise, which can cause failures. Given t ...

Dear Jarin, I'm not sure of the exact reason why you received the error message when reading the a2f file. However, it appears that your zrn.a2f file may not have been calculated using the specified input parameters. The zrn.a2f file indicates a Fermi window of 0.4 eV, while you specified fsthick as ...