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Updated: Oct 28, 2025

Measuring the Densities of Aqueous Glasses at Cryogenic Temperatures
Published on: June 28, 2017
Extreme case of density scaling: The Weeks-Chandler-Andersen system at low temperatures
Eman Attia1, Jeppe C Dyre1, Ulf R Pedersen1
1Glass and Time, IMFUFA, Department of Science and Environment, Roskilde University, P.O. Box 260, 4000 Roskilde, Denmark.
Abstract:
This paper studies numerically the Weeks-Chandler-Andersen system, which is shown to obey hidden scale invariance with a density-scaling exponent that varies from below 5 to above 500. This unprecedented variation makes it advantageous to use the fourth-order Runge-Kutta algorithm for tracing out isomorphs. Good isomorph invariance of structure and dynamics is observed over more than three orders of magnitude temperature variation. For all state points studied, the virial potential-energy correlation coefficient and the density-scaling exponent are controlled mainly by the temperature. Based on the assumption of statistically independent pair interactions, a mean-field theory is developed that rationalizes this finding and provides an excellent fit to data at low temperatures.
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