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 $L_{ \parallel}$ to crossover radius $r_{ \rm c}^{ \mathbf k}$ 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.
Categories: cond-mat.mtrl-sci cond-mat.stat-mech