[CP2K:1753] Re: Total dipole via LOCALIZATION - bug?

[Fawzi Mohamed]

The thing my code did and is not done now is simply to remove jumps by  
L/2*pi, and output also the finite derivative of the dipole, this  
could also be added to the present code as an option.

If you use the total dipole of a periodic system setting the reference  
to COAC is not so useful, and does not allow you to remove the jumps  
easily.

Fawzi
On 3-feb-09, at 11:54, viki wrote:

>
> 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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>