Note: Sound velocities of generalized Lennard-Jones ($n-6$) fluids near freezing

Abstract

In a recent paper [S. Khrapak, Molecules {\bf 25}, 3498 (2000)] the longitudinal and transverse sound velocities of conventional Lennard-Jones systems at the liquid-solid coexistence were calculated. It was shown that the sound velocities remain almost invariant along the liquid-solid coexistence boundary lines and that their magnitudes are comparable with those of repulsive soft sphere and hard sphere models at the fluid-solid phase transition. This implies that attraction does not affect the magnitude of sound velocities at the fluid-solid phase transition. This paper provides further evidence to this by examining the generalized Lennard-Jones $n$-6 fluids with $n$ ranging from $12$ to $7$ and demonstrating that the steepness of repulsive term has only a minor effect on the magnitude of the sound velocities.