EPW Forum

Hi Pravin,

You can use EPW for 2D-polarons. The tutorials are uploaded at this link

https://epw2024.oden.utexas.edu/74-schedule

Please look at Friday tutorial WEL 1.316.

Regards,
Shashi

Hi Fale Li, I suspect that Fermi energy is not correctly calculated because you commented out fermi_energy in your input file. When you interpolate band structure, you use points along a path, so the code will not calculate the Fermi energy correctly. When you provide uniform k-mesh, the code ...

Hi Jianguo, To eliminate NaN values, check if the temperature is very close to Tc. If so, try increasing npade to a significantly larger value. If that doesn't resolve the issue, consider increasing the cut-off for the imaginary frequency. Additionally, the Tc estimated from the machine learning ...

Hi Fale Li,

Are you interested in the phonon dispersion plot? If yes, please add band_plot = .true. and phonselfen=.false.

Please let me know if you still have issues.

Regards,
Shashi

Hi Subham, If you check the code in EPW/src/supercond.f90, you’ll find that we have provided references for the Allen-Dynes modified McMillan formula in the strong coupling limit. Specifically, these correspond to Eqs. (34–38) from Allen and Dynes, Phys. Rev. B 12, 3 (1975). For your reference, I am ...

Hi Fale Li, There are a few issues with your input parameters that I would like to clarify. The setting ephwrite=.true. is not compatible with filkf=.true. and filqf=.true. since it requires uniform k and q grids. Additionally, you are using phonselfen=.true. along with eliashberg=.true., which are ...

Hi Subham,

Could you confirm whether you are using the latest version of EPW v5.9? If not, I recommend using the latest version and try again.

Best regards,
Shashi

Hi Jhosamelly, You cannot calculate mobility using EPW without including phonons. The phonon data is essential for this calculation. As Hari mentioned, you can try to speed up your calculations by optimizing the k-mesh and energy cutoff , but you’ll need to perform a convergence test to check a ...

Hi Animesh, The writing to ephmatf depends on the number of pools. When you change the number of processors from 8 to 16, the number of k-points per pool differs. Therefore, it is hard to compare the ephmatf1 from both these calculations. So, if you want to verify your results using different sets ...

Hi Subham,

In EPW v5.9 (https://gitlab.com/epw/q-e), we incorporated the Allen-Dynes formula for Tc estimation with strong coupling corrections.

Hope this helps! Let me know if you need any further details.

Best regards,
Shashi