Coarse-Grained Counterions in the Strong Coupling Limit

Abstract

Recent Monte Carlo simulations [A. G. Moreira and R. R. Netz: Eur. Phys. J. E 8 (2002) 33] in the strong Coulomb coupling regime suggest strange counterion electrostatics unlike the Poisson–Boltzmann picture: when counterion–counterion repulsive interactions are much larger than counterion–macroion attraction, the coarse-grained counterion distribution around a macroion is determined only by the latter, and the former is irrelevant. Here, we offer an explanation for the apparently paradoxical electrostatics by mathematically manipulating the strong coupling limit.