[Pw_forum] negative freqency

[Eyvaz Isaev]

Dear Zahra,

--- On Tue, 10/7/08, zahra sadat naghavi <szs_naghavi at yahoo.com> wrote:

> I run ph.x for a grid of qs and there is not any > negative freqency but as I run matdyn.x they emerg what > should I do? 

Can you submit the picture? 
In my experience this might happen due to insufficient number of dynamical matrices.

Bests,
Eyvaz.

-------------------------------------------------------------------
Prof. Eyvaz Isaev, 
Theoretical Physics Department, Moscow State Institute of Steel & Alloys, Russia, 
Department of Physics, Chemistry, and Biology (IFM), Linkoping University, Sweden 
Condensed Matter Theory Group, Uppsala University, Sweden 
Eyvaz.Isaev at fysik.uu.se, isaev at ifm.liu.se, eyvaz_isaev at yahoo.com