[Pw_forum] from frc_blk : error #

[Stefano de Gironcoli]

dear  Sanjeev,

matdyn computes the weight of the contribution of a pair of atoms to the 
dynamical matrix on the basis of their separation. the weight is 1 if 
the separation is inside an expanded Wigner-Seitz cell, 0 if it is 
outside and an appropriate fraction if it is ON one or more planes at 
the  border [wsweight=1/(number_of_planes +1].
This check is done with a threshold (10-6 in PW/src/wsweight.f90) and 
for numerical reasons the result may not be correct if the atomic 
coordinated are defined at the same level of accuracy.

you can try to
1) play with this threshold (for instance, reduce it to 10^-5) and see 
if this solves the problem and results make sense.
2) increase the accuracy used in atomic coordinates of your system.

best

  stefano



On 08/02/2012 08:40 AM, Sanjeev Gupta wrote:
> Dear PWSCF user
> Greetings
>
>
>
> *For Phonon calculation:*
> After successfully running q2r.in. But matdyn.in running
> &input
>       amass(1)=65.409,
>      amass(2)=15.9994,
>      asr='crystal',
>      flfrc='zno.fc',
>      flfrq='zno.freq'
> /
> ...............
> .............
>
> I am getting this error like this
>
>   %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
>       task #         0
>       from frc_blk : error #         1
>       wrong total_weight
>   %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
>
> Please suggest me.
> Best Regards
> Sanjeev
>
>
>
>
>
>
>
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> Pw_forum at pwscf.org
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