ABSTRACT
Continuous random network (CRN) structures (Polk 1971, Connell and Temkin 1974) have been made which seem to be in good agreement with experimental data. A common feature of all the CRN models is that they allow ' a priori ' free rotation of the tetrahedra along their common axis, in contrast with the fixed values present in the crystalline tetrahedral structures. Small distortions of the tetrahedron unit itself are also permitted. However, the random character of the CRN is never complete : a statistical analysis of these structures never shows a flat distribution of dihedral angles, but does show some preferential values related to the ring statistics. In the CannellTemkin (CT) model (Connell and Temkin 1974), the random character is also reduced by the restriction to even-membered rings only.
