The previously developed particle mesh Ewald method is reformulated in terms of efficient B‐
spline interpolation of the structure factors. This reformulation allows a natural extension of
the method to potentials of the form 1/rp with p≥ 1. Furthermore, efficient calculation of the
virial tensor follows. Use of B‐splines in place of Lagrange interpolation leads to analytic
gradients as well as a significant improvement in the accuracy. We demonstrate that
arbitrary accuracy can be achieved, independent of system size N, at a cost that scales as N …