Modeling multibody effects in ionic solutions with a concentration dependent dielectric permittivity.

We report a new strategy to parametrize effective ion-ion potentials for implicit solvent simulations of charged systems. The effective potential includes a pair term and a Coulomb term that by means of a concentration dependent dielectric permittivity takes into account multibody effects. We demonstrate that this approach allows us to accurately reproduce the solution osmotic properties and the ion coordination up to concentrations of 2.8 M aqueous NaCl.