The ABINIT Users Mailing List ( CLOSED )

[Thanusit Burinprakhon <thanusit@kku.ac.th>]

Dear All
I'm trying to perform the phonon band structure calculation of AlAs by
following the tutorials lessons trf2_1 to trf2_7 (Abinit 5.4.4). At the end of
trf2_6, it is suggested that we should run a convergence study on the k and q
point grids (separately !) and as well as on the energy cut-off. I'm just 
about
to do that but not I'm sure about the following points:

1. Regarding the "q point grids", does this refer to the input parameters
"ngqpt"in the input file of the "anaddb" program?(as listed below)

------Part of trf2_4.in----------
!Wavevector grid number 1 (coarse grid, from DDB)
  brav    2         ! Bravais Lattice : 1-S.C., 2-F.C., 3-B.C., 4-Hex.)
  ngqpt   4  4  4   ! Monkhorst-Pack indices
  nqshft  1         ! number of q-points in repeated basic q-cell
  q1shft  3*0.0
------------------------------------------------------

2. What are the calculated parameters we have to look at in these convergence
studies? Is it enough just to examine the convergence of phonon frequency?

3. Is there any example on the phonon dos calculation by "anaddb"?

All suggestions and comments are appreciated.

Regards,
Thanusit Burinprakhon

Physics department, 
Khon-Kaen university, Thailand.