[gmx-users] PME accuracy

[Vincent Ballenegger]

Berk Hess wrote:

> The 2 kJ/mol nm Bert gets are exactly on the same order of the error 
> in the two ion system.
> It is important to know if the errors for a many charge system cancel 
> out and as Bert has
> shown they seem to do. 

My plot shows indeed deviations in the forces of about 2 kJ/mol.nm. 
Since these deviations are oscillatory, they may well cancel out on 
average. In my problem (two ions + solvent), this effect is important, 
because I want the asymptotic force between the two ions to be correct!

Vincent

>