ON THE STRUCTURE OF SILICA GLASS AND WATER

A simple mechanism for alteration of the local structure of SiO2 or H2O polymorphs by flipping of Si-O-Si or O-H---O groups is given. This operation provides a natural basis for the interpretation of structural transformations. When applied in an ordered manner the flipping motivates the transition between crystalline polymorphs. Similarly the disorder produced by random flipping models the corresponding melting transition, yielding simple descriptions of the structure of silica glass and water.