Efficient dynamic simulations of charged dielectric colloids through a novel hybrid method

Abstract

Modern particle-based simulations increasingly incorporate polarization charges arising from spatially nonuniform permittivity. For complex dielectric geometries, calculation of these induced many-body effects typically requires numerical solvers based upon boundary-element methods, which very significantly increase the required computational effort. For the special case of dielectric spheres, such as colloids or nanoparticles, we recently proposed a semianalytical spectrally accurate hybrid method that combines the method of moments, the image-charge method, and the fast multipole method. The hybrid method is efficient and accurate even when dielectric spheres are closely packed. Here, we extend the method to the evaluation of direct and induced electrostatic forces and demonstrate how this can be incorporated in molecular dynamics simulations. The choice of the relevant numerical parameters for molecular dynamics simulations is discussed in detail, as well as comparisons to the boundary-element method. As a concrete example, we examine the challenging case of binary crystal structures composed of close-packed dielectric colloidal spheres.