how to set fsthick and.....

[1504463450]

Dear friends
Is there any skill and basis for setting parameters "fsthick", wscut" and" muc" in EPW calculation?
Yours sincerely
Shi

[hpaudya1]

Hi Shi,

You need to get your results converged with respect to fsthick and wscut. Typically, we use;

fsthick = 4 times the maximum phonon frequency (and also please set your degaussw to 1/4 of fsthick)
wscut = 10 times the maximum phonon frequency
and
muc = 0.1 to 0.2 (you can compare your Tc with expt. to estimate muc)

I hope it helps.

Happy EPWing,
Hari

[Kunsa]

How to get maximum phonon frequecy for wscut setting? when I see ph.out file it is too big 10HZ. Any one help me?

[hpaudya1]

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 freq.).

I hope it helps.

Happy EPWing,
Hari