Strong geometric frustration in model glassformers


Icosahedra form as Wahnström liquids cool down.


We consider three popular model glassformers, the Kob-Andersen and Wahnström binary Lennard-Jones models and weakly polydisperse hard spheres. Although these systems exhibit a range of fragilities, all feature a rather similar behaviour in their local structure approaching dynamic arrest. In particular we use the dynamic topological cluster classification to extract a locally favoured structure which is particular to each system. These structures form percolating networks, however in all cases there is a strong decoupling between structural and dynamic lengthscales. We suggest that the lack of growth of the structural lengthscale may be related to strong geometric frustration.

C. P. Royall, A. Malins, A. J. Dunleavy & R. Pinney
Journal of Non-Crystalline Solids 407, 34-43 (2014)

DOI: 10.1016/j.jnoncrysol.2014.08.017
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