EPW Forum

Hi Shubham,

You can go through the first paper of the EPW code; https://www.sciencedirect.com/science/a ... via%3Dihub, where you can see the decay plots in Fig. 2.

Happy EPWing,
Hari

Hi Shubham,

As long as you have all bands inside the Fermi window (ie. from -fsthick to +fsthick) and the Wannier functions are well decayed (please plot and compare your Hamiltonian and el-ph decay) it should not affect the Tc and SC gap.

Happy EPWing,
Hari

Hi Shubham, The negative value of superconducting gap is not physical. However, we do not restrict the calculation based on the -/+ value of the superconducting gap, any numerical value is possible in the calculation. If the negative value is too small, that can the a numerical error. I recommend yo...

Hi Huan Tran, First: It looks like your Pade calculation is not converged. I recommend you to decrease the value of "npade" (the default value is 90, https://docs.epw-code.org/doc/Inputs.html#npade) Second: The memory requirement depends mainly on number of k/q points, number of bands inside the Fer...

Hi Sahil,

I think, it would be fine if your calculation is conversed. I always recommend to check the convergence.

Happy EPWing,
Hari

Hi Sahil, I see the following temp( 1) = 0.20000 K Solve isotropic Eliashberg equations on imaginary-axis Total number of frequency points nsiw( 1) = 9235 Cutoff frequency wscut = 1.0001 With nsiw(1) = 9235, N = npade * nsiw(1) / 100 (will make even by adding one if it is odd) = 8312 (with default v...

Hi Sahil,

Could you please share your 'prefix.a2f' file. I will investigate the problem myself and let you know the problem and possible solution.

Happy EPWing,
Hari

Hi Kunsa, By default, Quantum ESPRESSO prints phonon frequency in THz and cm-1 units. Look at them, and find what is the maximum (no need of exact value). For e.g. in MgB2, I get ~800 cm-1 maximum phonon frequency, which is ~0.099184 eV and choose wscut = 1 eV (which is close to 10 times max. ph fre...

Hi dsc,

Could you double check your phonon is calculated and the corresponding files are saved correctly in 'dvscf_dir = './save'' directory?

Happy EPWing,
Hari

Hi Prachi,

This is just a message in a restart calculation from https://gitlab.com/QEF/q-e/-/blob/devel ... pw.f90#L92. If your first step is done correctly, and corresponding files are written with no issue, no do not need to worry with this message.

Happy EPWing,
Hari