Both Source0 and Source1 are code sources to simulate a periodic boundary system separated into two chambers by two identical cylindrical porous membranes. Each chamber contains two types of elastic spherical particles that differ only in size. Source0 will have one chamber filled with particles and the other kept constantly empty (vanish.c), while Source1 will have densities in both, one higher than the other for both types. When existant, the density is controlled by a fixed chemical potential, giving us a grand-canonical system. Run0 and Run1 are corresponding input instances for initial conditions.
All motion and elastic collisions involved are modelled classical mechanically, and the program outputs files for density fluctuations so as to determine equilibrium. Meanwhile, it also computes the mean values of pressure and temperature over time, as well as particle flux. These are then used to calculate each particle type's permeability (=flux/pressure gradient) and the separation factor (permeability ratio) between them, which are the principle investigated quantities.