Dynamics of thermal vibrational motions and stringlike jump motions in three-dimensional glass-forming liquids Available to Purchase

Using molecular dynamics simulation on a glass-forming liquid in three dimensions, we investigate the thermal vibrational motions, the configuration changes caused by stringlike jump motions, and their close correlations. The heterogeneous vibrational motions are visualized in terms of a vibration length S_i(t) defined for each particle i. The structure factor for the inhomogeneity of S_i(t)² is also calculated, which exhibits considerable long wavelength enhancement. By examining the birth times of strings, they are shown to appear collectively and intermittently. We show that particles with larger S_i(t) tend to trigger jump motions more frequently at later times than those with smaller S_i(t). We also show that the particles with fewer bonds tend to have larger S_i(t) and participate more frequently in the stringlike motions.