Molecular dynamics results for the dynamic Prigogine-Defay ratio are presented for two glass-forming liquids, thus evaluating the experimentally relevant quantity for testing whether metastable-equilibrium liquid dynamics to a good approximation are described by a single parameter. For the Kob-Andersen binary Lennard-Jones mixture as well as for an asymmetric dumbbell model liquid a single-parameter description works quite well. This is confirmed by time-domain results where it is found that energy and pressure fluctuations are strongly correlated on the alpha-time scale in the NVT ensemble; in the NpT ensemble energy and volume fluctuations similarly correlate strongly.
Cite
@article{arxiv.cond-mat/0611514,
title = {Feasibility of single-order parameter description of equilibrium viscous liquid dynamics},
author = {Ulf R. Pedersen and Tage Christensen and Thomas B. Schrøder and Jeppe C. Dyre},
journal= {arXiv preprint arXiv:cond-mat/0611514},
year = {2009}
}