Two-domain structure and dynamics heterogeneity in a liquid SiO2

Molecular dynamics simulation is employed to investigate the diffusion mechanism, dynamics and structure heterogeneity in a liquid SiO2 at ambient pressure and different temperatures. To explore these phenomena we propose the link-cluster and init-bond functions. The simulation shows that during a moderately long time the liquid has a two-domain structure that consists of separate mobile and immobile domains. These types of domains differ strongly in the rate of atomic rearrangement and fraction of defective atoms. The simulation also reveals a strong correlation between mobility of atoms and init-bond function which evidences the bond-breaking mechanism and that the reactions are non-uniformly distributed in the space. The liquid exhibits dynamics heterogeneity which is accompanied with the structure heterogeneity and cooperative movement of atoms via like-molecules SixOy.