Low melting temperature and liquid surface layering for pair potential models

We have recently proposed [Phys. Rev. Lett. 87, 166101 (2001)] that any isotropic fluid should exhibit surface layering at its liquid-vapor interface above the triple temperature provided that the system has a low triple temperature. In this article we present an extensive study of systems with different isotropic pair interactions, some of which present a very low triple temperature. We have confirmed that surface layering is a general characteristic of very cold liquids, independent of the specific shape of the potential, and that only pair potentials presenting a low triple-point temperature do exhibit surface oscillations; in other cases layering is preempted by solidification. Finally, we study the damping of surface oscillations due to capillary waves and conclude that for any model pair potential the temperature threshold below which layering would be observed for the typical experimental transverse sampling sizes is 15% of the critical temperature. (C) 2002 American Institute of Physics.