(334a) Application of Ewald Summations to Long-Range Dispersion Forces

We present results illustrating the effects of using explicit summation terms for the r^-6 dispersion term on the interfacial properties of a Lennard-Jones fluid and SPC/E water. For the Lennard-Jones fluid, we find that the use of long-range summations, even with a short ``crossover radius,'' yields results that are consistent with simulations using large cutoff radii. Simulations of SPC/E water demonstrate that the long-range dispersion forces are of secondary importance to the Coulombic forces. In both cases, we find that the ratio of box size L_|| to crossover radius r_c^k plays an important role in determining the magnitude of the long-range dispersion correction, although its effect is secondary when Coulombic interactions are also present.

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