[Pw_forum] phonon dispersion jagged

[Serge Nakhmanson]

Dear Paolo,

I did a very quick test. Yes, now the problem is fixed and the
dispersion curves are smooth again.

Thank you and, I guess, thanks to Andrea as well,

S.


Paolo Giannozzi wrote:
> 
> On Oct 28, 2008, at 12:46 , Ante Bilic wrote:
> 
>> The calculated dispersion curves were in very good agreement
>> with those in the literature, except they look shockingly ugly! For
>> some reason they are not smooth, but rather jagged.
> 
> are you by any chance running a version later than July 1st (v.4.0.1
> and later)? I am afraid that a change I recently made:
> http://www.democritos.it:8888/O-sesame/rlog?f=O-sesame/PH/rigid.f90
> in order to fix a possible bug and to speedup calculations obeyed the
> "bug sum rule", i.e. one bug fixed, one new bug added (thanks to
> Andrea Dal Corso for noticing this). Please change the two
> instructions at lines 92 and 124 of file PH/rigid.f90:
>    if (geg > 0.0 .and. geg < gmax ) then
> into
>   if (geg > 0.0 .and. geg/alph/4.0_DP < gmax ) then
> recompile q2r.x, re-run the "q2r.x" part, report if this fixes your (and
> Serge's) problem
> 
> Paolo
> ---
> Paolo Giannozzi, Dept of Physics, University of Udine
> via delle Scienze 208, 33100 Udine, Italy
> Phone +39-0432-558216, fax +39-0432-558222
> 
> 
> 


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  Serge M. Nakhmanson               phone: (630) 252-5205
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