Static properties and time correlation functions of fluids with steeply repulsive potentials

There has been much interest in recent years in the properties of fluids composed of particles that interact through potentials with a ‘tunable’ softness, particularly for highly repulsive particles close to the hard-sphere limit. Much of this interest is driven by the granular media and colloid communities, but there are fundamental issues concerning the physics of fluids in general that can be addressed with such model systems. In this report we continue our series of investigations into the properties of an example of such a fluid, the so-called inverse power or soft-sphere fluid which is composed of particles interacting through a pair potential, ϕ (r)=ϵ (σ/r) n , where n measures the steepness or stiffness of the potential. We review the current state of our knowledge of the properties of such fluids and point out some still unresolved areas. We present the results of new computations for a range of n values and densities. Interest is focused on the time correlation functions as exemplified by the fo...