[Pw_forum] Can I use resluts of gamma point to calculate the phonon dispersion curve?

[Peng Tao]

I see, thank you Stefano. 


> -----Original Messages-----
> From: "stefano de gironcoli" <degironc at sissa.it>
> Sent Time: Tuesday, September 24, 2013
> To: "PWSCF Forum" <pw_forum at pwscf.org>
> Cc: 
> Subject: Re: [Pw_forum] Can I use resluts of gamma point to calculate the phonon dispersion curve?
> 
> in order to generate interatomic force constants that then give you 
> phonon dispersions you need to compute dynamical matrices for a grid of 
> q points (1d grid in your case i would say). gamma is a point always 
> present in the grid so you can reuse its data.
> how many additional points you need to add depends on how far the 
> interatomic force constants extend and how large is your system.
> for large systems even just gamma might be enough (need to be tested)
> stefano
> 
> On 09/24/2013 03:19 AM, Peng Tao wrote:
> > Dear all,
> >
> > I have calculated the phonon frequencies of gamma point before, and now I'm planning to
> > calculate its phonon dispersion curve. Can I use the results of gamma point? If not, phonon
> > of the gamma point needs to be recalculated, which is really a waste of time.
> >
> > My system is quite large and one-dimensional, so the gamma point is exclusively important.
> > If it is possible to make use of previous results, plenty of time will be saved.
> >
> > Thank you very much!
> >
> >
> > Warmest regards,
> > Peng Tao
> >
> >
> >
> > --
> > -------------------------------------------------------------------
> > PH.D. candidate Peng Tao
> > Magnetism and Magnetic Materials Division
> > National Laboratory for Material Science
> > Institute of Metal Research, Chinese Academy of Sciences
> > Phone  +86-024-83978751
> > -------------------------------------------------------------------
> >
> >
> >
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PH.D. candidate Peng Tao 
Magnetism and Magnetic Materials Division
National Laboratory for Material Science
Institute of Metal Research, Chinese Academy of Sciences
Phone  +86-024-83978751
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