Fig. 5: Sketch of the spatial distribution of the molecules participating in the βJG-process at a given time.
From: Experimental evidence of mosaic structure in strongly supercooled molecular liquids
The molecules undergoing the βJG-relaxation (red spheres) are highly mobile and, after a time of the order of \({\tau }_{{\beta }_{{\rm{JG}}}}^{{\rm{DS}}}\), perform larger spatial excursions than the rest of the molecules (white spheres). These spatial excursions are, on average, of the order of those prescribed by the Lindemann criterion for crystal instability19. These "un-caged" molecules form a (close to) percolating cluster. The sketch is based on an experimentally measured configuration for a colloidal glass of hard spheres (volume fraction 0.61) reported in ref. 44 but has no direct connection to the discussion reported in that study. The cluster of mobile molecules was obtained by randomly selecting particles with a probability of 0.25, according to the here discussed estimate for the fraction of molecules participating in the βJG-relaxation at \({\tau }_{{\beta }_{{\rm{JG}}}}^{{\rm{DS}}}\) (relaxation strength).
