[Pw_forum] Error in phonon calculation using matdyn.x

[Stefano de Gironcoli]

increasing the threshold to 1.d-7 will probably not help..
I think the total weight you have is 7.5 instead of 8.0...
is your cell very anisotropic ?
try to increase the VERY VERY SAFE RANGE to 3 times nr1,nr2,nr3 ...

stefano

On 03/29/2011 03:00 PM, Eyvaz Isaev wrote:
> Hi,
>
> Find subroutine frc_blk(...)    inside matdyn.f90 the next line:
>
>          IF (ABS(total_weight-nr1*nr2*nr3).GT.1.0d-8) THEN
>
> Might be due to some numerical noise this condition is not fulfilled. Then try
> 1.d0d-7 (recompile matdyn.f90 using "make ph")  and see what happens. If not,
> then one has to analyze your input files.
>
> Bests,
> Eyvaz.
>
>   -------------------------------------------------------------------
> Prof. Eyvaz Isaev,
> Department of Physics, Chemistry, and Biology (IFM), Linkoping University,
> Sweden
>
> Theoretical Physics Department, Moscow State Institute of Steel&  Alloys,
> Russia,
>
> isaev at ifm.liu.se, eyvaz_isaev at yahoo.com
>
>
>
> ----- Original Message ----
> From: mayank gupta<mayankaditya at gmail.com>
> To: pw_forum at pwscf.org
> Sent: Tue, March 29, 2011 6:00:15 AM
> Subject: [Pw_forum] Error in phonon calculation using matdyn.x
>
> Dear All I am doing pwscf and phonon calculation for Y2O3. In 2x2x2 Q
> mesh it  generates 6 irreducible q points (yo.dyn* files). The phonon
> frequency calculation using  matdyn.x run I got error message
>
> 7.5000000000000000
>       from frc_blk : error #         1
>       wrong total_weight
>       stopping ...
>
> What could be the possible error.
>
>
> Thanks
>
>
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