Computational aspects of the two-dimensional propagation of R-matrices on MPPs

The simulation of electron collisions, at intermediate energies, with atoms, ions and molecules in highly excited Rydberg states is a physically important and computationally challenging problem. A suitable computational technique, to meet this challenge for the general two-electron problem, involves an adaptation of the intermediate energy R-matrix approach, in which the (r₁, r₂) plane of the inner region is partitioned into a set of connected subregions and a global ℜ-matrix is propagated, in two dimensions, across this plane. In this paper we examine the computational aspects of this technique and, in particular, describe a parallel strategy for exploiting the architecture of distributed memory parallel computers.