  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.
