Sound Velocities of Generalized Lennard-Jones (n - 6) Fluids Near Freezing.

In a recent paper [S. Khrapak, Molecules 25, 3498 (2020)], the longitudinal and transverse sound velocities of a conventional Lennard-Jones system 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 considerably affect the magnitude of the 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 the repulsive term has only a minor effect on the magnitude of the sound velocities. Nevertheless, these minor trends are identified and discussed.