[Pw_forum] thanks

Nicola Marzari marzari at MIT.EDU
Sat Mar 31 19:44:09 CEST 2007

saman ghaderyan wrote:
> hi
> thanks
> i am reading your helping now
> but my problem is when i have matdyn files in a lot of q_vectors
> how i plot them together .
> thanks again

You get the dynamical matrices on a uniform mesh of q vectors,
FFT in real space to get the real space interatomic force
constants, you apply translational sum rules, and transform back
with a regular Fourier transfrom at any arbitrary q. Diagonalize
at that q, and you have the w_{n,q} phonon dispersion.

If system has a FCC Bravais lattice (e.g. Silicon) it is convential
to plot them from L to Gamma to X to K to X, or permutations.


Prof Nicola Marzari   Department of Materials Science and Engineering
13-5066   MIT   77 Massachusetts Avenue   Cambridge MA 02139-4307 USA
tel 617.4522758 fax 2586534 marzari at mit.edu http://quasiamore.mit.edu

More information about the users mailing list