EPW Forum

Hi Jianguo, I suppose you are working on the anisotropic Eliashberg calculation. Please check the following points: (1) Did you use mp_mesh_k? If not, please use "mp_mesh_k = .true." (2) Which value of iverbosity did you set? You do not need to set "iverbosity = 2" to solve the ME equations, "iverbo...

Dear Timon, I would like to know more about the files output from EPW in this job. Especially I want to know whether prefix.a2f was an empty file, and whether any newer files than prefix.a2f were output. Since you use iverbosity == 2, some optional files such as prefix.lambda_pairs and prefix.lambda...

Hi Ilias, Unfortunately, ncarrier is ignored in superconductivity calculations. You can change the Fermi level manually by setting "efermi_read" and "fermi_energy" instead. However, even though you calculate a superconducting gap and see the dependence of Fermi level using them, you cannot output a ...

Hi John,

Yes, you can change the format to human-readable one by changing "FORM = 'unformatted'" to "FORM = 'formatted'".
Note that the file size may become larger than that of the binary format.

Best,
Hitoshi

Hi Animesh,

We do not provide an option to change the file format, so you have to modify "write_ephmat()" in EPW/src/io_eliashberg.f90 to change the format yourself.

Best,
Hitoshi

Dear Yi-Ming, EPW code calculates the electron and phonon linewidths by using the Eqs. (8)-(9) in the paper S. Ponce et al., Comput. Phys. Commun. 209, 116 (2016). As the equations show, the electron linewidth seems sensitive to temperature because it has the Bose distribution. The phonon linewidth ...

Dear jqhuang, It is not easy to modify the source code and know in a single calculation a good threshold value. It may be time-consuming for you. As a quick fix, I recommend you to set use_ws = false to avoid using Wigner–Seitz cell. Note that use_ws = true often leads to better Wannier interpolatio...

Hi, Several approximations exist for the delta function. From equations (1) and (2) (see the attached image), we use the fact that the imaginary part of 1/(x-iε) can be regarded as approximately Gaussian with infinitesimal ε and σ. Since both ε and σ are infinitesimals but different quantities, you ...

Hi Shubham,

For your calculations using muc=0.0 and 0.01, what values did you use for parameters such as wscut? Did the "Max Superconducting gap" remain positive when the "Min Superconducting gap" was negative?

Best,
Hitoshi