Systematic selection of surface-site density and mass

Determine how to systematically and reliably select the density and mass of discrete surface sites used to couple colloidal particles to the solvent in multiparticle collision dynamics simulations.

Background

Multiparticle collision dynamics simulations represent colloidal particles by discrete surface sites that participate in solvent collisions and thereby mediate hydrodynamic coupling. Prior studies reported conflicting effects of surface-site density and mass on inertial artifacts, velocity autocorrelation functions, and long-time diffusion coefficients. Because the surface-site density is a necessary discretization parameter but should not introduce artificial dependence into suspension transport properties, the paper identifies the systematic and reliable selection of both surface-site density and site mass as an unresolved issue. The subsequent analysis investigates several strategies, including matching the solvent-cell mass, average site mass, total particle mass, and both total mass and moment of inertia; however, the explicit unresolved statement appears in the introduction before those results are presented.