EPW Forum

Dear Shudong, nel is equivalent to tot_charge (in absolute value), that is, the added electrons in your unit cell. epsiHEG is the average \epsilon_\infty e.g. from your dfpt calculation. meff is the average band effective mass for your material. The electron-plasmon coupling is implemented as in m a...

Dear Chris,

The matrix elements printed are the modulus of the 'full' ones, that is, what is called with the somewhat deprecated name 'g^SE' in that link (second equation).

Best
Carla

Hi Chris,

Just a clarification - when you set ibrav=2 do you also obtain the correct interpolated
phonon dispersion within EPW (simple asr)?

Best
Carla

Good to know Chris, thank you!

Carla

Hi Chris,

Thanks for letting us know, we will try and fix the bug and for now warn not to use ibrav 0!

Carla

Hi Chris, Looking in that subroutine, the only other reason for printing that error message (if you uncomment the amass) is: IF (ntyp.ne.ntyp_.or.nat.ne.nat_.or.ibrav_.ne.ibrav.or.abs ( & celldm_ (1) - celldm (1) ) .gt.1.0d-5) call errore ('readmat2', & 'inconsistent data', 1) which means th...

Dear Chris,

I think you only need to uncomment amass(1) and amass(2)

Best,
Carla

Dear Nandan,

Have you checked that the interpolated band structure and phonons that you get from epw are correct?

Best,
Carla

Dear Chris, It seems indeed there is some problem with the interpolation, already at the phonon dispersions level, so most likely also with the matrix elements. Looking at your phonons plots m the dispersion looks good if you use the force constants from q2r, but the fact that it looks so different ...

Dear Chris, The cumulant expansion is a method for calculating the spectral function. If you want to see the contribution of different phonon modes to the e-ph self-energy, you can set verbosity=3. Beware that this will only follow the phonon mode index, rather than the actual nature of the phonon b...