RE: [ESPResSo-devel] Nsquare cellsystem and folded positions

[Limbach, Hans Joerg, LAUSANNE, NRC-FS]

Hi again,

Why it doesn't make sense...
... Put one particle in a box. Apply periodicity in 1D. Then you have always 
two images of the original particle which are at the very same distance. Which 
one you choose to calculate the force?

And that's right you can not simulate a system with periodic bounderies (and 
minimum image convention) where the box is smaller then 2 times the maximal 
interaction range.

Documentation of all this would mean to write a textbook about simulations in 
general not about Espresso. 

Hanjo 
 

> -----Original Message-----
> From: address@hidden 
> [mailto:address@hidden On 
> Behalf Of Olaf Lenz
> Sent: lundi, 13. août 2007 15:09
> To: ESPResSo developers' mailing list
> Subject: Re: [ESPResSo-devel] Nsquare cellsystem and folded positions
> 
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> 
> Hi!
> 
> Limbach, Hans Joerg, LAUSANNE, NRC-FS wrote:
> > What is a periodically replicated system together with the 
> nsquare cellsystem?
> > Answer: A strange thing. So, no wonder it behaves strange.
> 
> Why should that be strange? Using the minimum image 
> convention, the behaviour is completely well-defined.
> Otherwise, how can you simulate a small system with a box 
> length between
> 2 and 3 cutoff distances?
> 
> > P.S. There is no box for the nsquare cellsystem and thus no folding!
> 
> Ok. Not, that this is documented anywhere....
> 
> Olaf
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