Velocity correlations in a family of simple soft core liquids

摘要

We have used molecular dynamics to study velocity correlation functions in a family of model liquids with continuous repulsive interaction potentials. As the softness of the potential was changed, systematic variations were found in the negative region of the correlation function. The use of a pure repulsive potential somewhat softer thanrminus;12resulted in dynamic features very similar to an ordinary Lennardhyphen;Jones (12ndash;6) liquid, and a still softer core induced oscillations in the correlation function. The observed behavior is interpreted in terms of the temporal coherence of backscattering events.