COMPUTER-MODELING STUDIES OF 4-2 COORDINATED GLASSES

Completely computer-generated models of 4-2 coordinated glasses have been constructed using an algorithm which allows a systematic investigation of the parameter-space describing amorphous networks. This paper describes the application of this algorithm to two very different glasses in the AX2 system: SiSe2 which is found to be based on a structure consisting of randomly oriented chains of edge-sharing Si(Se1,2)4 tetrahedra and six-membered rings, and SiO2 whose structure is consistent with a continuous random network of corner-sharing tetrahedra. It is now possible to modify these algorithms for the study of GeS2 and GeSe2 and hence to investigate the possible existence of "outrigger rafts" and rings in these glasses. © 1990.