[Pw_forum] matdyn.x problem

[Subhradip Ghosh]

Hi,

I was trying to run matdyn.x for an artificial structure. I am
getting the following error in the very beginning:

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
     from matdyn : error #        -1
     non-analytic term for q=0 missing !
 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
As a result I am getting negative frequencies in some of the
cases in a arbitrary way.

I tried with a older version of PWSCF(version 1.0.3
probably)using the same force constant file. I did not get any
such message and there were no negative frequencies. The
results were reasonable.

What could be the remedy?

Subhradip
*******************************************************************
                      Subhradip Ghosh
                   Post doctoral Fellow
                   Department of Materials Science & Engineering
                   University of Illinois at Urbana-Champaign
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