Lennard-Jones based molecular dynamics simulations of capillarity fluctuations in flat, 2D symmetric tilt grain boundaries show that fluctuation in the high symmetry 38.2° Σ7 boundary was consistent with capillarity wave theory, with a grain boundary stiffness of 0.31ε/r0. The low-symmetry 30° Σ∞ boundary exhibits peaks at certain modes, indicative of vicinal cusps in the Wulff plot.

Direct Two-Dimensional Calculations of Grain Boundary Stiffness. Z.T.Trautt, M.Upmanyu: Scripta Materialia, 2005, 52[11], 1175-9