SPARTA is a parallel DSMC code for performing simulations of low-density gases
in 2D or 3D. Particles advect through a hierarchical Cartesian grid that
overlays the simulation box. The grid is used to group particles by grid cell
for purposes of performing collisions and chemistry. Physical objects with
triangulated surfaces can be embedded in the grid, creating cut and split grid
cells. The grid is also used to efficiently find particle/surface collisions.

SPARTA runs on single processors or in parallel using message-passing techniques
and a spatial-decomposition of the simulation domain. The code is designed to be
easy to modify or extend with new functionality.

SPARTA was developed at Sandia National Laboratories, a US Department of Energy
(DOE) laboratory.