Partitioning 3D space for parallel many-particle simulations

In a common approach for parallel processing applied to simulations of many-particle systems with short-ranged interactions and uniform density, the cubic simulation box is partitioned into domains of equal shape and size, each of which is assigned to one processor. We compare the commonly used simple-cubic (SC) domain shape to domain shapes chosen as the Voronoi cells of BCC, FCC, and HCP sphere packings. The latter three are found to result in superior partitionings with respect to communication overhead. Scaling of the domain shape is used to extend the range of applicability of these partitionings to a large set of processor numbers. The higher efficiency with BCC and FCC partitionings is demonstrated in simulations of the sillium model for amorphous silicon.