EPW Forum

Hi Nina, Thank you for responding. I have already seen that tutorial. There are several issues: 1. If the k/q grid is 250^3/250^3, the use of mp_mesh_k which reduces the BZ points to wedge points is still a very large number (115211 to be exact). Even if you continue to restart, it will take at ...

After running many tests, I conclude that the impurity scattering in EPW requires iterative BTE, adaptive smearing and a regular fine k/q mesh. The calculation cannot be broken into smaller segments. I would appreciate a simple yes or no (hopefully someone other than me) as to whether the above ...

In the c-BN example for impurity scattering, degaussw=0 (adaptive smearing). I have two quick questions:
1. Does the impurity routine work only with degaussw=0?
2. Does adaptive smearing work for segments of fine k or q?

Thanks,
Vahid

I did manage to break up the calculation by setting IBTE to .false. and removing the magnetic fields.
Vahid

Dear EPW community, I have a system which requires a 250x250x250 k/q grid to converge the conductivity without impurity. I had to break up this big job into k-segments and q-segments to finish it. To add impurity, I tried to break up the q-grid into segments but the code crashed. Does the impurity ...

The velocities of the modes can be obtained by simply doing the following single loop: CALL vmewan2blochp(xxq, nmodes, nrr_q, irvec_q, ndegen_q, uf, vmefp(:, :, :), wf(:, qind), rws, nrws) DO imode=1,nmodes vmeqf(:, imode)=REAL(vmefp(:, imode, imode), KIND = DP) ENDDO I was averaging the six modes ...

Dear EPW users, I am using EPW-5.4.1. To extract phonon velocities of Si (I am actually interested in the +/- sign of the velocity not the correct magnitude), I have added the following to the ephwann_shuffle.f90: CALL vmewan2blochp(xxq, nmodes, nrr_q, irvec_q, ndegen_q, uf, vmefp(:, :, :), wf ...

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 ...