Direct Wolf summation of a polarizable force field for silica

TL;DR

This paper extends the Wolf summation method to efficiently compute dipolar interactions in a polarizable silica force field, enabling large-scale simulations with linear scaling and validated accuracy.

Contribution

It introduces a spherical truncation extension of Wolf summation for dipolar interactions in silica, improving computational efficiency for large systems.

Findings

Linear scaling of computational effort with system size.

Accurate estimation of error terms in the summation method.

Successful simulation of silica's microstructure and thermodynamics.

Abstract

We extend the Wolf direct, pairwise r^(-1) summation method with spherical truncation to dipolar interactions in silica. The Tangney-Scandolo interatomic force field for silica takes regard of polarizable oxygen atoms whose dipole moments are determined by iteration to a self-consistent solution. With Wolf summation, the computational effort scales linearly in the system size and can easily be distributed among many processors, thus making large-scale simulations of dipoles possible. The details of the implementation are explained. The approach is validated by estimations of the error term and simulations of microstructural and thermodynamic properties of silica.