The effect of molecular shape anisotropy on surface melting

We report molecular dynamics (MD) simulations of the behaviour of the (1010) and (0001) crystal-vapour interfaces of Lennard-Jones dimers near the triple point. For slightly anisometric molecules, where the bulk melts from an orientationally disordered state, both interfaces were found to surface melt, with behaviour resembling that of the atomic Lennard-Jones system. In contrast, at larger anisometries, where the molecules are orientationally ordered close to the triple point, the (1010) face exhibits a first-order surface melting transition, while the (0001) face does not surface melt at all.