[MMTK] Importing electrostatic potential to MMTK

Konrad Hinsen hinsen at cnrs-orleans.fr
Wed Oct 10 07:55:00 UTC 2007


On 07.10.2007, at 16:27, Pentti Frondelius wrote:

> Furhermore, I would like to ask if it is possible to calculate an  
> Ewald
> sum for a given point charge system with given periodicity? I'm  
> aware of
> the fact that MMTK can calculate Ewald sums in molecular dynamics,  
> but can
> I directly do it for a given system, which is not related to any  
> dynamic
> simulation? Ofcourse one could implement the summation with own Python
> code, but naturally it is faster to use already implemented and tested
> code.

Yes, you can calculate any energy, including electrostatic energies  
by Ewald summation, directly:

	print universe.energy()

or if you want the terms separately:

	print universe.energyTerms()

However, Ewald summation is implemented only for 3D-periodic  
rectangular systems. This will be extended to non-rectangular systems  
as soon as I find the time, but there are no plans to provide 1D or  
2D periodic systems at the moment.

Konrad.
--
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Konrad Hinsen
Centre de Biophysique Moléculaire, CNRS Orléans
Synchrotron Soleil - Division Expériences
Saint Aubin - BP 48
91192 Gif sur Yvette Cedex, France
Tel. +33-1 69 35 97 15
E-Mail: hinsen at cnrs-orleans.fr
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