A large-scale molecular dynamics computer simulation was used for analyzing structures and diffusion in amorphous aluminum silicate. Melt at 6100 to 2300K and the glass configurations were fully equilibrated. Most of the aluminum and silicon atoms were four-fold coordinated by oxygen atoms at temperatures as high as 4000K. The results showed that the diffusion dynamics in amorphous aluminum silicate were much faster than in SiO2. The self-diffusion of O and Al was similar and was 2 to 3 times higher than that of Si.

Structure and Diffusion in Amorphous Aluminum Silicate: a Molecular Dynamics Computer Simulation. Winkler, A., Horbach, J., Kob, W., Binder, K.: Journal of Chemical Physics, 2004, 120[1], 384-93