When you perform a calculation of electron-phonon interaction coefficients
with the tetrahedron method,
you have to use an offset q-point grid in order to avoid a singularity
at q = ; you can perform this calculation as follows:
occupation = "tetrahedra_opt"
and K_POINT automatic
.
lshift_q = .true.
and electron_phonon = ""
(or unset it)
to generate the dynamical matrix and
the deformation potential (in _ph*/{prefix}_q*/
) of each q.
electron_phonon = "lambda_tetra"
.
You should use a denser k grid by setting nk1
, nk2
, and nk3
.
Then lambda*.dat
are generated; they contain
alpha2f.x
with an input file as follows:
&INPUTPH ! The same as that for the electron-phonon calculation with ph.x : / &INPUTA2F nfreq = Number of frequency-points for a2F(omega), /Then
.a2F.dat
.
There is an example in PHonon/example/tetra_example/
.