[Pw_forum] Q2R code and phonon at gamma

[David Foster]

Dear users,
I calculated phonons at gamma point of a 2*2 supercell of graphene after vc-relax>scf.
all frequencies are positive.
Now, I need to use q2r.x code to impose ASR on them.
The ph.x generated one matdyn file which I named it as "graph22G.dyn", 
but q2r.x code searches for graph22G.dyn0. I didn't use grid of q-point, so, I 
only have one dyn file.
I also used the trick of the header of q2r.f90 file, with nr1,nr2,nr3, nfile, and filin:
nr1=150, nr2=150, nr3=300
nfile=1
graph22G.dyn
but q2r.x, in this case, shows the error of namelist.

I am not sure that the q2r.x can be used for gamma point only, or it is only for grid of q-points.
Should I use phcg.x instead of ph.x for gamma point?
Any guide will be appreciated.



Regards

David Foster

Ph.D. Student of Chemistry