The structure of vitreous silica: Validity of the random network theory

Abstract

It is shown that the random network theory of glass structure accounts satisfactorily for the observed x-ray and neutron radial distribution functions of vitreous silica, out to interatomic distances of at least 0·8 nm (8 Å). This result is based on the study of a molecular model containing sample atomic arrangements consistent with the general precepts of the random network theory. Analysis of a range of molecular models, discussed briefly, suggests that the distribution of bond angles may not be the only factor determining the overall agreement between theoretical and experimental radial distribution functions. The distribution of molecular loops in the network seems to be of importance in this context. Details of the satisfactory model are given in the Appendix, in the form of a list of atomic coordinates and nearest neighbour connections.