Correlations of System Mobility with Various Scalar Metrics

Molecular dynamic simulations of chain systems were performed in order to investigate the relationships between the system mobility and thermostatic quantities. Systems consisted of pearl-necklace chains along with single site penetrants. Both attractive and repulsive systems (based on the cut-off of the Lennard-Jones potential) were simulated. The diffusion coefficients, D, for the chains and penetrants were then found for a variety of temperatures (T) and density combinations. D/T was found to be a single-valued function of a thermostatic quantity that we denoted as a ``scalar metric.'' Four scalar metrics were found. Since, through the master curve, the mobilities for all temperature-density points can be extrapolated to a single zero, a unique ideal glass transition can be proposed to exist. Consequently, a scalar metric can be used as a ``distance'' measure to this ideal glass transition.