We report on Parallel Tempering Monte Carlo investigations of the influence of surface attraction and geometry on adsorption-induced chiral separation and phase behavior in two model systems. The two model molecules exhibited distinct chiral self-assembly outcomes in previous surface-free, two dimensional calculations. Here, by considering atomistic apolar rigid surfaces, we found that the adsorbed patterns and geometries were largely unaffected by surface attraction or layout. When the lattice spacing and/or atom size of the substrate were varied, however, several types of commensuration effects were observed, often leading to an enhancement of separation quality from the surface-free case. (C) 2011 Elsevier B.V. All rights reserved.