EPW Forum

Hello, The non-zero population indicates a problem such that the results cannot be trusted. This is likely due to your 4x4x4 q-point grid instead of 4x4x1. Before doing mobility calculation, you need to make sure that the electronic bandstructure and phonon bandstructure are correctly interpolated. ...

Hello, Note that 2D materials are not officially supported yet in EPW. You can use the EPW input variable system_2d = .true. at your own risk (with the version QE 6.8). You will need to comment out the check in EPW/src/epw_readin.f90 In any case, your phonon should also be planar like your k-grid: n...

Dear Marcelo Albuquerque, The mobility is independent on the carrier concentration. Therefore if you change ncarrier, the mobility should (almost) not change. If you want to look at high carrier concentration, you have to manually shift the Fermi level in the CB. You then have to redo the phonon cal...

Dear Yaokun Ye, Thank you for your interest in EPW and welcome to the forum. It seems you are looking at the change of potential on the real-space grid (something similar to a deformation potential) and not the electron-phonon matrix element. From your Fig.1 you can see that the real part and imagin...

Dear Max, Eq. 10 is the Boltzmann transport equation which is an equality in steady state between the driving force (i.e. the electric field) and the scattering (i.e. the electron-phonon scattering). If you want to understand the physics behind, I can recommand the review https://iopscience.iop.org/...

Dear Amir, Welcome to the EPW forum ! What you want to do seems difficult and computationally expansive. However you could do an approximation and just simulate SiC and constrain the lattice parameter to be the same as SiO2. This might be a too strong approximation tough. As a rule of thumbs, if you...

Dear Hyuan, Thank you for your question. The Fig.S2 in my paper is done at fixed fine k and q interpolated grids. If instead you increase the k/q grids when you decrease the smearing, it should indeed converge. I think that the \eta->0 limit exists for a grid density -> infinity. Best wishes, Samuel

Hello joshie, You are correct, in the public version of EPW the "iverbosity = 3" keyword will only give you the mode resolve self-energy, which is closely linked with the scattering rates. We have implemented the mode resolved scattering rates and and its contribution to the mobility as part of a la...

Dear Manasa, It is slightly difficult to answer this as it depends on the version of EPW you are using and the option you chosen. Easiest it to check for yourself. You can look in the EPW/src/printing.f90 subroutine. If the velocity vkk_all and occupation vector f_out are in crystal when printed the...

Dear EPW users, EPW currently does not officially support 2D materials. Only a few changes are required to make it work and we plan to release it soon. In the meantime, you can perform calculations in 2D materials but need to treat it as a 3D one with vacuum. This means that you need to have some (a...