[MMTK] Energy evaluation bug?

Konrad Hinsen hinsen@cnrs-orleans.fr
14 Oct 2001 21:23:44 +0200


Adam Hixson <hixsonc@yahoo.com> writes:

> I find that the problem seems to be in the electro-
> static bit, as when I use the .energyTerms() method
> this is the part that does not add up.
> 
> This is using an electrostatic cutoff, apparently
> the subsets are not yet ready for ewald sums.

This is not a question of "not yet", it is a more fundamental problem.
I am not aware of any reasonable definition for "electrostatic
interaction energy between two subsets" in the presence of periodic
boundary conditions that would make your sum come out correctly. The
problem is the implicit presence of a neutralizing background charge
density in Ewald summation.

Konrad.
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