EPW Forum

Dear Shashi, It seems that the reason we are getting two different wedge points is the EPW version. I was using QE-7.0 and in that version of EPW, wedge points are not the same as the latest development QE version. Perhaps this was a bug which got fixed at some point but there is no documentation on ...

Dear Shashi, Attached please see the EPW input files, and the epw.out file. The scattering rate includes 41917 kpoints. Attached is also the file mesh_k output by PW/tools/kpoints.x. There are 21084 wedge points. It is possible that the issue is related to the use of two different carbon atoms, C ...

Dear EPW users, When I run graphene with a 500x500 k-grid, QE reduces the job to 21084 k-points in the wedge as expected. However, EPW creates a 41917 k-point wedge with the same k-grid. The issue is likely due to the use of a Gamma-centred BZ by QE versus a [0:1] k-grid by EPW. Are there any ...

Dear Shashi,

Thank you for this clarification. I will use the develop branch to get the conductivity and then compare to BTE and IBTE results.

Best,
Vahid

Dear Shashi, Thank you for this clarification but the change in Fermi energy occurs before IBTE starts (input Fermi level=2.8249eV). Here is the relevant section of the output: ============================================================================================= BTE in the self-energy ...

Dear Shashi, I ran an IBTE calculation on the Pb (no SOC) example in the EPW folder. Attached are the input and output EPW files. The Fermi energy is set to 11.7176eV in the input. In the output near the end where the iterative conductivities are printed, the Fermi level is changed by EPW to 11 ...

Hi Shashi, Thank you for your input. Using assume_metal = .true. did result in getting the IBTE conductivities for different iterations. I was wondering what should the tag "int_mob" be for IBTE in metals? I set it to false and am getting ~ 54% of the expected conductivity. In addition, the input ...

Dear EPW users, I have calculated the el-ph matrix elements for a metal with EPW-5.4.1 and have restarted to calculate the scattering rates and the IBTE. The following tags are set: elph = .true. epbwrite = .false. epbread = .false. epwwrite = .false. epwread = .true. wannierize = .false. scattering ...

Dear EPW Community, In transport.f90, the transition probability is defined as ! transition probability ! (2 pi/hbar) * (k+q-point weight) * g2 * ! { [f(E_k+q) + n(w_q)] * delta[E_k - E_k+q + w_q] + ! [1 - f(E_k+q) + n(w_q)] * delta[E_k - E_k+q - w_q] } The first term is absorption (+w_q) and the ...

Dear H. Lee, I changed the q-grid to 12x12x12, matching the k-grid. The electron and phonon dispersions from EPW match those of QE. The PSP is norm-conserving. After some digging into the code, I believe the mismatch between emission and absorption coupling constant comes from the phase factor exp ...