[Pw_forum] supercell in matdyn.x

[Paolo Giannozzi]

On Apr 18, 2012, at 13:51 , babr aram wrote:

> Dear all, I would like to use matdyn.x to calculate phonon dos
> but i don't know the difference between
> (1): making a 2*2*2 supercell and running ph.x calculation
> for supercell and then running matdyn.x to calculate phonon dos and
> (2):  running ph.x calculation for unit cell (or primitive cell)  
> and then
> matdyn.x for supercell (for l1=2, l2=2, l3=2)

they should actually yield the same result, provided the latter option
still works. It was written 20 years ago or so to implement the so- 
called
"effective-mass approximation" in GaAs/AlAs superlattices and alloys.
Several years ago it was still working, but I doubt it has been used
since.

P.
---
Paolo Giannozzi, Dept of Chemistry&Physics&Environment,
Univ. Udine, via delle Scienze 208, 33100 Udine, Italy
Phone +39-0432-558216, fax +39-0432-558222