Total dipole via LOCALIZATION - bug?

[viki]

Please, this code was written originally by Fawzi (so I think) for an
article which we wrote jointly on IR spectra - the explicit purpose of
that PBC code was to avoid jumps in total dipole derivative due to
periodicity. I have an old version of QS with Fawzi's programming in
which this problem did not exist - but it does not include dispersion
which I now need. I would rather not install the code again unless
this particular problem was addressed - is there any way to ask the
person who fixed the bug, if he addressed this particular problem?
Thanks much! Victoria

On Jan 31, 7:09 pm, Juerg Hutter <hut... at pci.uzh.ch> wrote:
> Hi
>
> there was a bug fix regarding the PBC dipole recently:
>
> Fri Jan 9 18:32:09 2009 UTC (3 weeks ago) by vondele
>
> Are you running an updated version?
>
> The Berry phase dipole is only defined within modulo L/2Pi.
> Jumps of multiples of this value are expected to appear.
>
> You can also calculate the total dipole moments without
> localization with
>
>   CP2K_INPUT / FORCE_EVAL / DFT / PRINT / MOMENTS
>
> There you can set
>   REFERENCE COAC
>
> this will minimize the number of jumps by setting the
> reference point to the center of atomic charges, i.e.
> the contribution to the dipole from the nuclear charges is
> zero. The same applies to the localization based method.
>
> regards
>
> Juerg Hutter
>
> ----------------------------------------------------------
> Juerg Hutter                   Phone : ++41 44 635 4491
> Physical Chemistry Institute   FAX   : ++41 44 635 6838
> University of Zurich           E-mail: hut... at pci.uzh.ch
> Winterthurerstrasse 190
> CH-8057 Zurich, Switzerland
> ----------------------------------------------------------
>
> On Sat, 31 Jan 2009, v.... at fh.huji.ac.il wrote:
>
> > Hello,
> > I am running
> >       &LOCALIZATION
> >          &TOTAL_DIPOLE
> >            &EACH 1
> >                &END
> >          &END TOTAL_DIPOLE
> >       &END LOCALIZATION
> > with the objective to calculate system dipole derivative as a function
> > of time (I need the IR spectrum). The system is periodic (one unit
> > cell of clathrate hydrate, which includes water, H2S and ethylene
> > oxide), DZVP-BLYP with Grimme van der Waals correction.
>
> > So here is a problem - now and then the dipole derivative jumps to
> > some preposterously huge value (positive or negative). These are
> > isolated points. To me it seems as if Berry phase formula which is
> > supposed to correct for periodicity does not work, although it is
> > supposed to be a default. Any advice? Thanks, Victoria Buch
>
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