The Local Density of Collective Basin Hops Required to Relax Topological Constraints to α Relaxation is Temperature-Independent

Analysis of the intermediate scattering function from neutron scattering in real liquids, or from simulated liquids yields two distinct modes of motion corresponding to the exploration of inherent state basins and hopping between these basins. We quantify the time-dependent fraction of particles that have undergone interbasin hops in atomistic and model systems in the liquid and supercooled liquid regimes. From our analysis, we provide evidence that the local network of constraints to α relaxation fails at a local fraction of basin crossing events that is fixed and temperature-independent for a given system. The fraction of interbasin hops at which the constraint network fails appears to vary with the class of liquid and may reflect the properties of the constraint network.