Pathways for diffusion in the potential energy landscape of the network glass former SiO2

• DOI: 10.1063/1.5005924
• Publication Date: 2017-10-16T13:08:50Z
• Authors: S. P. Niblett; M. Biedermann; D. J. Wales; V. K. de Souza
• Keywords: Energy landscape; Particle (ecology)

We study the dynamical behaviour of a computer model for viscous silica, archetypal strong glass former, and compare its diffusion mechanism with earlier studies fragile binary Lennard-Jones liquid. Three different methods analysis are employed. First, temperature time scale dependence constant is analysed. Negative correlation particle displacements influences transport properties in silica as well liquids. suggest that difference between Arrhenius super-Arrhenius diffusive results from competition caging scale. Second, we analyse dynamics using geometrical definition cage-breaking transitions was proposed previously formers. find this accurately captures bond rearrangement mechanisms control open network liquids, reproduces constants at low temperatures. As same method applicable to both formers, can scales these two types systems. spent chains correlated cage breaks characteristic correlations system persist an order magnitude longer than those system. investigate origin by sampling potential energy landscape comparing it model. no qualitative landscapes, but several metrics liquid rougher more frustrated. Metabasins smaller contain fewer high-barrier processes. This probably leads observed separation scales.