Various properties of vitrifying liquids are correlated with the dispersity of the dynamics, the latter reflected in the magnitude of the nonexponentiality parameter, βK, describing the distribution of relaxation times. These properties include the mean relaxation time, τα, the fragility, and the dynamic crossover. The correlations with βK are observed in both experimental data and the results from molecular dynamics simulations on Lennard-Jones (LJ) type systems. Another, rather obvious property to correlate with βK is the dynamic heterogeneity, which can be quantified from the number of molecules, Nc, dynamically correlated over a time span τα. For a given LJ system, Nc can be rigorously calculated and we find that it does indeed correlate with βK over a range of thermodynamic conditions. However, the analysis of experimental data for a broad range of real materials, wherein an approximation is required to obtain Nc, reveals the absence of any relationship between Nc and βK among different materials.

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