[Pw_forum] Plotting phonon dispersion

[Vahid Askarpour]

Once you get all the .dyn files from the ph.x run, use the following input to q2r.x to get the force constants:

 &input
   fildyn=’Si.dyn', zasr='simple', flfrc=’Si.ifc2’
/

Then use the following input to matdyn.x:

&input
    asr='simple',  amass(1)= 28.0855
    flfrc=’Si.ifc2', flfrq=’Si.freq', q_in_band_form=.true.
/
6  ! number of high-symmetry points
0.0 0.0 0.0 200  
0.0 0.0 1.0 200  
etc.

The coordinates of the high symmetry points should be in cartesian coordinates. 200 points will be calculated for each segment. The phonon dispersion is in the .gp output file.

Cheers,

Vahid

Vahid Askarpour
Department of Physics and Atmospheric Science
Dalhousie University,
Halifax, NS, Canada

> On Feb 19, 2018, at 4:54 AM, elchatz at auth.gr wrote:
> 
> Hello all,
> 
> I am using ph.x to get the phonon frequencies and dynamical matrices  
> for an epw.x calculation, however, I would like to plot my phonon  
> dispersions from the ph.x calculation for far, as for example is shown  
> in
> 
> http://epw.org.uk/Documentation/B-dopedDiamond
> 
> I am lost as to how I can do that. My ph.x file is as follows,
> 
> &inputph
>   prefix   = 'Si',
>   epsil    = .false.,
>   fildyn   = 'diam.dyn',
>   ldisp    = .true.
>   fildvscf = 'dvscf'
>   nq1=6,
>   nq2=6,
>   nq3=1,
>   tr2_ph   =  1.0d-12,
>   recover = .true.
>  /
> 
> Do I need to use q2r.x and matdyn.x to the files for plotting?
> 
> 
> Thank you
> 
> 
> 
> -- 
> Dr. Eleni Chatzikyriakou
> Computational Physics lab
> Aristotle University of Thessaloniki
> elchatz at auth.gr - tel:+30 2310 998109
> 
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