The structural properties of SiO2 liquid during cooling have been investigated by
molecular dynamics simulations. The interatomic forces acting on the particles are calculated by the
modified Tersoff potential parameters. The glass transition temperature and structural properties of
the resulting SiO2 system at various temperatures have been investigated. The fivefold
coordinations of Si and threefold coordinations of O atoms were observed, and the coordination
defects of system decrease with decreasing temperature up to 17 % at 300 K. The self-diffusion
coefficients for Si and O atoms drop to almost zero below 3000 K. The structures were distorted at
high temperatures, but very stable atomic network persisted up to high temperature in the liquid
state.
Concentration dependence of intracrystalline self-diffusion in zeolites