Simulations of Coulomb systems with slab geometry using an efficient 3D Ewald summation method

Abstract

We present a new approach to efficiently simulate electrolytes confined between infinite charged walls using a 3d Ewald summation method. The optimal performance is achieved by separating the electrostatic potential produced by the charged walls from the electrostatic potential of electrolyte. The electric field produced by the 3d periodic images of the walls is constant inside the simulation cell, with the field produced by the transverse images of the charged plates canceling out. The non-neutral confined electrolyte in an external potential can be simulated using 3d Ewald summation with a suitable renormalization of the electrostatic energy, to remove a divergence, and a correction that accounts for the conditional convergence of the resulting lattice sum. The new algorithm is at least an order of magnitude more rapid than the usual simulation methods for the slab geometry and can be further sped up by adopting a particle-particle particle-mesh approach.

Charge neutrality breakdown in confined aqueous electrolytes: Theory and simulation

“…Ref [19], and a residual potential of self-interaction. The short-range electrostatic potential at position r r r is φ S (r r r) = N j=1 q j erfc(κ e |r r r − r r r j |) ǫ w |r r r − r r r j | ,…”

“…Open symbols represent the MC results, the solid lines are profiles obtained from the bulk-HNC approximation, while dashed lines stand for the bulk-MSA approach. We note that the recently developed efficient MC method 19 , allows to very accurately perform statistics while using small grid sizes over the simulation box. The resulting ionic profiles are able to precisely capture the fine details of the double layer structure in the vicinity of the charged surfaces, providing an excellent basis for testing the validity of different theoretical approaches.…”

“…The details of all the derivations can be found in Ref. [19]. Here we will just present the applications of the algorithm to the present problem.…”

Lattice Model of an Ionic Liquid at an Electrified Interface

“…The damping parameter κ e is set to κ e = 5/L. The long-range electrostatic potential can be written as 67,75 φ L (r r r) =…”

Adsorption isotherms of charged nanoparticles

“…The electrostatic interactions are calculated by summing over all the periodic replicas of the system using Ewald summation method, modified for slab geometry [37,38]. Here we adopt a recently introduced efficient simulation algorithm developed specifically for this geometry [39]. The electrostatic energy of a periodically replicated system, containing N charged particles, is…”