Hi,
If you set
delta_approx=.true.
a2f=.true.
you should get the same results as for
eliashberg=.true.
If you want to understand the difference between the two methods used to evaluate the Eliashberg spectral function with or without the delta_approx you can take a look at the following discussion:
viewtopic.php?f=3&t=741&p=2441&hilit=delta_approx#p2441Another thing to keep in my is that eliashberg=.true. only works with uniform meshes why a2f=.true. can work with both uniform and random meshes.
The code can calculate a2fij(ik,iq,ibnd,jbnd,iwph) if you call the subroutine evaluate_a2fij found in superconductivity_aniso.f90
Best,
Roxana