The specific features of the dynamics of oxygen ions in melts at 2000K were investigated using the partially ionic potential approximation. It was demonstrated that the formation of defect complexes was a necessary condition for an oxygen diffusion event to be successful. Methods for generating defect complexes were described, and the lifetimes of these complexes were calculated. The structure of the defect complexes was determined. It was found that, in the Li2O-SiO2 melt, successful oxygen diffusion events occurred predominantly with the participation of fivefold-coordinated silicon ions. Threefold-coordinated defects began to predominate in the Na2O-SiO2 melt, and their role became crucial to diffusion in the potassium and cesium metasilicate melts. It was shown for the first time that free and threefold-coordinated oxygen ions could also be involved in the formation of defect complexes.

Defects and Oxygen Diffusion in Metasilicate Melts: Molecular Dynamics Simulation. Berezhnoi, G.V., Boiko, G.G.: Glass Physics and Chemistry, 2005, 31[2], 145-54