THEORETICAL-STUDY OF THE INTERSTICE STATISTICS OF THE OXYGEN SUBLATTICE IN VITREOUS SIO2

The interstice statistics of the oxygen sublattice of the canonical inorganic glass-former silica have been investigated theoretically for a number of structural models of upsilon-SiO2. It is found that spheres with radii smaller than 2.41 angstrom minus the oxygen radius can travel freely through a model of upsilon-SiO2 made by Feuston and Garofalini. The nonoverlapping interstice size distribution can be described by a log-normal function. The concentrations of interstitial sites in these models with radii greater than the size of rare-gas atoms agree with the experimental values from gas-solubility studies.