EPW Forum

Dear all,

I found three files containing the Eliashberg function, "prefix.a2f", "prefix.a2f.01" and "prefix.a2f_iso". I also found that the file "prefix.a2f" and "prefix.a2f_iso" were generated only when "eliashberg=.true." is trigged. The e-ph constant printed in the three files are a little different. For example, the summed el-ph coupling in the files "prefix.a2f", "prefix.a2f.01" and "prefix.a2f_iso" are 4.5243227, 4.8310526 and 4.5243227. What's the differences among the three files?

Bests

Hi,

The file *.a2f contains the Eliashberg spectral function as a function of frequency (meV), calculated using various smearing parameters (default number 10). This is calculated using Eqn. (11) in Computer Physics Communications 209 (2016) 116133.

The file *.a2f_iso contains the Eliashberg spectral function as a function of frequency (meV) . The second column is the Eliashberg spectral function corresponding to the first smearing value in *.a2f . The remaining columns in *.a2f_iso (3 x number of atoms) contain the mode-resolved Eliashberg spectral function (there is no specific information on which modes correspond to which atomic species).

The file *.a2f.01 contains the Eliashberg spectral function as a function of frequency (meV), calculated using various smearing parameters (default number 10). By default, this is calculated based on the expression for the phonon self-energy from Eqn. (9) in Computer Physics Communications 209 (2016) 116133. If you want to use Eqn. (11) and obtain the same value as in file *.a2f, you will need to set up the flag delta_approx = .true. in the input file along with the flags a2f=.true. and selfen_phon=.true.

Best,
Roxana