On Tue, 2012-09-11 at 15:22 +0200, Thomas Gruber wrote: > Can someone give me a hint how to calculate my phonon > frequencies with acoustic sum rule? just heard a suggestion: since you have just one phonon wave-vector, you can use dynmat.x instead of q2r.x+matdyn.x P. -- Paolo Giannozzi, IOM-Democritos and University of Udine, Italy