Fourrier?[edit]

As far as I know, P3M is _not_ a Fourier-based Ewald Summation method. P3M mainly means that on top of the PM where particles interact through a grid instead of directly, you add a close range part for the interaction of each close-by particles, since PM introduces errors when particles overlap. The Fourrier aspect of PM/P3M comes into play when you solve statically for the fields, mainly using Poisson's equation. But you could solve the field dynamically, using the FDTD algorithm.

So Fourrier is for static PM/P3M and not for dynamic PM/P3M where FDTD is used instead. Nicolas Bigaouette (talk) 16:33, 3 September 2009 (UTC)[reply]