[Pw_forum] Phonon calculation at high pressure

[Eyvaz Isaev]

Dear Bipul,

--- On Wed, 8/27/08, Bipul Rakshit <bipulrr at gmail.com> wrote:
 
> 
> But for B2 structure I am getting many -ve frequencies.
> Although ScAs (B2) structure is stable at some high 
> pressure, so do i have to set some pressure
> in the system and then I have to do the phonon 
> calculation?

Yes, this is the correct way. Just set up tstress=.true. and tprnfor=.true. in order to monitor what is pressure in your high pressure ScAs phase.

> 
> In simple words, how can i do the phonon calculation for ScAs (B2) structure which is structure at high pressure?
> 

In simple words, decrease the lattice parameter and see what say above mentioned keywords about pressure, then continue your phonon calculations.  

Bests,
Eyvaz.
> 
> -- 
> Bipul Rakshit
> PhD Student,
> Barkatullah University,
> Bhopal 462026,
> MP, India
> _______________________________________________


-------------------------------------------------------------------
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
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