We show that the dynamics of soft-sphere systems with purely repulsive interactions can be described by introducing an effective hard-sphere diameter determined using the Andersen-Weeks-Chandler approximation. We find that this approximation, known to describe static properties of liquids, also gives a good description of a dynamical quantity, the relaxation time, even in the vicinity of the glass transition.
@article{arxiv.1107.2583,
title = {Mapping the glassy dynamics of soft spheres onto hard-sphere behavior},
author = {Michael Schmiedeberg and Thomas K. Haxton and Sidney R. Nagel and Andrea J. Liu},
journal= {arXiv preprint arXiv:1107.2583},
year = {2011}
}