EPW Forum

Dear Vahid, Thanks for sharing the input/output files. The shift in Fermi energy printed during the IBTE calculation is expected as EPW recalculates the Fermi level at each temperature. When assume_metal=.true., the Fermi energy at the given temperature is estimated assuming a hole-type carrier. The ...

Hi Vahid,

IBTE works for metals in EPW. To enable it, please make sure to include the tag assume_metal = .true. in your EPW input file.

Let me know if you have any questions.

Best regards,
Shashi

Dear Donglin Guo, I hope Jae-Mo Lihm has already addressed your question. Regarding the error message, it suggests that symmetry-equivalent k -points have inconsistent eigenvalues. Could you please check the eigenvalue file you provided and verify whether the eigenvalues for symmetry-equivalent k ...

Hi,

Some of our team members are currently working on implementing the Seebeck coefficient and electronic thermal conductivity in EPW. We will share an update once the implementation is complete.

Regards,
Shashi

Hi Ashwath, 1,2) The fine grid you're using (18³) is quite coarse. To obtain converged values for λ and Tc, you'll need to increase both ` nkf ` and ` nqf `. If your Wannierization looks good and the decay plots are convincing, you should go ahead and increase the k/q grids. Using a coarse fine grid ...

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 ...