Fast Multipole Method
The Fast Multipole Method (FMM) calculates the potentials and forces which arise in various scientific applications such as molecular dynamics and plasma physics. All these applications have in common that long-range interactions between huge numbers of particles have to be calculated. The FMM allows the efficient computation of the interactions by means of expansions of the potentials and forces into multipole moments. The main idea of the FMM is to group remote charges together such that a collection of distant charges can be treated as one single charge. The FMM is a computational scheme how to manipulate the multipole expansions to achieve linear scaling with regard to the number of particles.
Our FMM implementation is based on a new approach to minimize the computation time for a given system of point charges by optimization of the FMM-parameters. Thus the new FMM implementation has a very low memory footprint and is able to compute systems consisting of more than a trillion point charges on BG/P.
Current activities include porting the FMM to BG/Q. The goal is a massively parallel version of the FMM to exploit today's computing resources.