The nature of the Si-O-Si bond angle distribution in vitreous silica

Experimental and modelling studies from the literature on vitreous silica have shown anomalous differences in the position of the maximum in the Si-O-Si bond angle distribution. A careful review of a purported refinement of experimental data indicates that the maximum at α=144° reported by Mozzi and Warren (1969) is, in fact, relatively insensitive to various analytical treatments. The original experimental bond angle distribution is, in turn, in reasonable agreement with Gaskell and Tarrant's computer-relaxed version of the Bell and Dean model (Gaskell and Tarrant 1980, Bell and Dean 1972).