Development of a lattice-sum method emulating nonperiodic boundary conditions for the treatment of electrostatic interactions in molecular simulations:A continuum-electrostatics study

摘要

Artifacts induced by the application of periodic boundary conditions and lattice-sum methods in explicit-solvent simulations of(bio-)molecular systems are nowadays a major concern in the computer-simulation community.The present article reports a first step toward the design of a modified lattice-sum algorithm emulating nonperiodic boundary conditions,and therefore exempt of such periodicity-induced artifacts.This result is achieved here in the(more simple)context of continuum electrostatics.It is shown that an appropriate modification of the periodic Poisson equation and of its boundary conditions leads to a continuum-electrostatics scheme,which,although applied under periodic boundary conditions,exactly mimics the nonperiodic situation.The possible extension of this scheme to explicit-solvent simulations is outlined and its practical implementation will be described in more details in a forthcoming article.