UNIT in &CELL and UNIT for output

Teodoro Laino teodor... at gmail.com
Tue Nov 25 13:58:44 UTC 2008


Hi Ondrej,

I have just a comment: Bohr/sec are not atomic units. So I agree with 
you about being careful, but
Bohr/sex cannot be called "atomic units": it's more a kind of messy mix.
Anyway.. I just committed an update that is: TRAJECTORY, FORCES and 
VELOCITIES in MOTION%PRINT have now a new keyword UNIT, which allow 
users to choose their favorite unit
of measure for the output quantities. This should avoid all confusion, 
and hopefully, make your life
easier (you can type there the unit you want in output.. as long as the 
unit has been defined in cp2k. For defined
units please see: http://cp2k.berlios.de/manual/units.html ).

Hope this will help.
In case of bugs, please, report them on this thread.
 
Teo

Ondrej Marsalek wrote:
> thanks, teo and toon. i have already computed my kinetic energies
> (using molmod to read the xyz file, btw).
>
> bohr/(hbar/hartree) is what i assumed, but one has to be careful. for
> example, in the gaussian 03 manual, you can find "... velocity in
> atomic units (Bohr/sec) ...". atomic units indeed...
>
> cheers,
> ondrej
>
>
> On Tue, Nov 25, 2008 at 10:53, Toon Verstraelen
> <toon.ver... at ugent.be> wrote:
>   
>> Hi Ondrej,
>>
>> The velocities are by default in atomic units, that is bohr/(hbar/hartree).
>>
>> A good reference for the conversion factors is the "CODATA Internationally
>> recommended values of the Fundamental Physcial Constants":
>>
>> http://physics.nist.gov/cuu/Constants/
>>
>> You can convince yourselves by computing the kinetic energy from these velocities.
>>
>> cheers,
>>
>> Toon
>>
>> Ondrej Marsalek wrote:
>>     
>>> hello everyone,
>>>
>>> i have not managed to get convincing information about the units of
>>> the velocities (from motion%print). searching through the source code
>>> did not help. looking in a more systematic way would probably do the
>>> trick, but i thought that this is such a trivial piece of information
>>> that it will be much faster yhis way, as i do not (yet?) know the
>>> structure of the source code.
>>>
>>> thanks for any info,
>>> ondrej
>>>
>>>       
>> --
>> ir. Toon Verstraelen
>> Center for Molecular Modeling
>> Ghent University
>> Proeftuinstraat 86
>> B9000 Gent
>> Belgium
>> Tel: +32 9 264 65 56
>> E-mail: Toon.Ver... at UGent.be
>> http://molmod.UGent.be/
>> http://molmod.UGent.be/code/
>>
>>     
>
> >
>   




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