A Modulated Bulk as a Fuzzy Boundary for the Simulation of Long-Ranged Inhomogeneous Systems

Abstract

A new method for simulating infinitely diluted inhomogeneous systems with long-ranged electrostatic interactions is presented. The inhomogeneous system extends its effect through a cell of the appropriate symmetry which is in turn immersed in a box with bulk solution. The boundary between the inhomogeneous and homogeneous regions can be freely crossed by the moving particles. The particles interact with the surrounding bulk through a discrete particle-particle modulated (short-ranged) Coulomb potential while the missing tail is recovered as a mean field contribution computed in a self-consistent way. The bulk particles undergo usual periodic boundary conditions. The modulated bulk as a fuzzy boundary (MBFB) method is checked through Monte Carlo simulations of the cylindrical model of polyelectroyltes using soft continuous potentials. Comparison with cell model simulations of the same model is done.

Key Words:

• Monte Carlo simulation
• methodology
• boundary conditions
• inhomogeneous systems
• polyelectrolytes