[Pw_forum] Plotting phonon dispersion

[Vahid Askarpour]

a) If you skip amass, I think the codes use the mass in the previous runs. 

b) Did you use ibrav=0 in the scf run? The high-symmetry points you defined are for ibrav=2. Otherwise, just specify the coordinates explicitly.

Cheers,

Vahid

> On Feb 19, 2018, at 9:29 AM, elchatz at auth.gr wrote:
> 
> 
> Thank you Vahid Askarpour.
> 
> I have two questions:
> 
> a) Is there a problem if I don't specify amass?
> 
> b) I have already done this procedure using the following files:
> 
> ph.x:
> 
> &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.
>  /
> 
> This run ok
> 
> q2r.in:
> 
>  &input
>   fildyn='diam.dyn',
>   flfrc='Si.rc'
>  /
> 
> This run ok
> 
> matdyn.in:
> 
>  &input
>     flfrc='Si.rc',
>     flfrq='Si.freq',
>     q_in_band_form=.true.
>  /
>  4
>  gG 50
>   X 50
>   M 50
>   gG 8
> 
> And I got the following error:
> 
> 
> %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
>      Error in routine find_bz_type (1):
>      Wrong ibrav
> 
> %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
> 
> Is it possible that this is because I messed up the names of the  
> files, or do I need to include explicitly the coordinates of the high  
> symmetry points?
> 
> 
> Regards
> 
> Eleni
> 
> 
> 
> 
> Quoting Vahid Askarpour <vh261281 at dal.ca>:
> 
>> 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
>>> 
>>> _______________________________________________
>>> Pw_forum mailing list
>>> Pw_forum at pwscf.org
>>> http://pwscf.org/mailman/listinfo/pw_forum
>> 
>> 
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> 
> 
> 
> -- 
> Dr. Eleni Chatzikyriakou
> Computational Physics lab
> Aristotle University of Thessaloniki
> elchatz at auth.gr - tel:+30 2310 998109
> 
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