EPW Forum

Hello,

In a metal, such as for superconductivity, you should have lpolar = .false.
Is this the case ?

Samuel

Dear Colleagues, We are happy to announce that on June 5-9 , 2023 we will hold the 2023 Virtual School on Many-Body Calculations using EPW and BerkeleyGW . This school will be the fourth event of a series that started in 2018 with the First International School on Electron-Phonon Physics from First ...

Dear PasanH, Thank you for your interest in EPW and welcome ! At present EPW only officially support bulk 3D materials. There is ongoing work on the 2D version of EPW, which should be release soon. The 1D version is also ongoing but will likely take more time. At present EPW only supports phonon-lim...

Dear sevenel, The phonon frequency of polar materials is ill defined exactly at q=Gamma. However it is well defined for q-->0 along a particular direction. Therefore you can safely remove the q=0 point from your plot and it should look exactly like the one obtained from matdyn.x You should not get n...

Dear Sylvester10, Please use the latest version of EPW for optimum experience. After having written the XX.wp file, you can perform a restart using: elph = .true. epbwrite = .false. epbread = .false. epwwrite = .false. epwread = .true. scattering = .true. scattering_serta = .true. int_mob = .false. ...

Dear calos818, I do agree with H. Lee that you could try using the latest tutorial on mobility from the school. However, in the particular case of the https://docs.epw-code.org/doc/GaN-II.html tutorial, it is based on the QE test-suite which means that it should be working (this is tested every nigh...

Dear Maitryj, A NaN in electron or hole mobility often results from the fact that your Fermi level is incorrectly set (fermi_energy) such that the Fermi level +- 'fsthick' value will fall within the bandgap. If this is the case, then there are no states that you are considering and therefore the mob...

Hello, You have to adapt 'ncarrier = -1E13' to 'ncarrier = 1E13' to do electron mobility and also change the position of the Fermi level to be closer to the CBM. I could also suggest doing the more recent tutorial from the 2021 school https://epw2021.oden.utexas.edu/74-schedule scroll down that page...

Hello, You have to use 'int_mob = .true.' However it is not recommanded for computational reasons (more expensive that treating them separately with separate Wannierization). In addition, it the case of a large bandgap, the intrinsic carrier concentration will be very low to the point that the bisec...

Dear Vahid, The version has been released in QE 6.8 and include Hall factor. Note that 2D with only 1 k/q point along the vacuum is possible in this case because it is graphene (a non polar material) and therefore no specific 2D electrostatic is needed for the Frohlich part. For 2D polar materials, ...