Phonon eigenvectors at just one q-point

Running Abinit Response calculations
1

Hi everyone,

I know it is possible to get the phonon eigenvectors as an output of anaddb after having calculated the phonons on a irreducible q-point grid, but I was wondering if there is a way to obtain the eigenvectors of the dynamical matrix at just one q-point without having to calculate them on a grid.

Is it as easy as just diagonalizing the dynamical matrix printed in the abinit output file, or is there some more manipulation needed?

Bests,
Luca

2

Hi Luca,

set nq1ph to 1 and q1phl = qx qy qz
and anaddb will FT^-1 to real space force constants (needed anyway if you want to interpolate to a random q) then FT back to the q you want.

The q1phl list accepts any q. The nqpath and qpath variables make a continuous path (you only specify the vertices). The full grid of q ng2qpt is used for DOS and thermodynamic calculations.