# Size of the rings

There are two possibilities for the numbering of rings. On the one hand, one can use the total number of nodes of the ring, therefore a N-membered ring is a ring containing N nodes. One the other hand, one can use the number of *network forming* nodes (ex: Si atoms in SiO\(_2\) and Ge atoms in GeS\(_2\) which are the atoms of highest coordination in these materials) an N-membered ring is therefore a ring containing 2\(\times\)N nodes. For crystals and SiO\(_2\)-like glasses the second definition is usually applied. Nevertheless the first method has to be used in the case of chalcogenide liquids and glasses in order to count rings with homopolar bonds (ex: Ge-Ge and S-S bonds in GeS\(_2\)) - See section 5.5.5 for further details.

From a theoretical point of view it is possible to obtain an estimate for the ring of maximum size that could exist in a network. This theoretical maximum size will depend on the properties of the system studied as well as on the definition of a ring.