  The dynamical properties and diffusive behavior of a collection of mutually
interacting particles are numerically investigated for two types of long-range
interparticle interactions: Coulomb-electrostatic and dipole-electrodynamic. It
is shown that when the particles are uniformly distributed throughout the
accessible space, the self-diffusion coefficient is always lowered by the
considered interparticle interactions, irrespective of their attractive or
repulsive character. This fact is also confirmed by a simple model to compute
the correction to the Brownian diffusion coefficient due to the interactions
among the particles. These interactions are also responsible for the onset of
dynamical chaos and an associated chaotic diffusion which still follows an
Einstein-Fick like law for the mean square displacement as a function of time.
Transitional phenomena are observed for Coulomb-electrostatic (repulsive) and
dipole-electrodynamic (attractive) interactions considered both separately and
in competition. The outcomes reported in this paper clearly indicate a feasible
experimental method to probe the activation of resonant electrodynamic
interactions among biomolecules.
