Hi Eyvaz, thanks for the answer!
> I just suggested that an unstable mode near Gamma > point might be a result of incorrectly determined > dynamical matrix (and then unstable mode) at X point, > and consequently, force constants obtained by q2r.x > are also not correct. I am not sure that you will be > able to get correct behavior of the phonon spectrum > (obtained using matdyn.x) with wrong interatomic force > constants. Are not you agree with this? Of course, I agree with this. I just assumed that the unstable mode at X is correct and the error is just close to Gamma, which can be quite reasonable (it was like this in my case). But of course, I was overlooking that it could be seen also in the opposite way. Best wishes, Katalin
