Discrete Charge Effects on an Infinitely Long Cylindrical Rod Model
  Two methods for determining the potential (\psi) around a discretely charged rod have been devised. The methods utilize the potential around the continuously charged rod (\bar{\psi}) as the reference where \bar{\psi} isdetermined by the Poisson-Boltzmann equation. The potential data are used to determine the theoretical radial distribution function (RDF) which is compared with MD simulation data. It is shown that the magnitude of the charge and size parameters very strongly affects the shape of the RDF's and consequently the thermodynamics. 
Ahmad A. J Agung and Christopher G. Jesudason
physics.comp-ph