network former

…known as a network-forming (NWF) cation—that is, a positively charged ion such as, in this case, silicon (Si⁴⁺). The four positive charges of the silicon ion lead it to form bonds with four oxygen atoms, forming SiO₄ tetrahedra, or four-sided pyramidal shapes, connected to each other at the corners.…

…number of the network-forming (NWF) ion, (2) the connectivity of the structure, as determined by the concentration of nonbridging oxygens, which, in turn, is determined by the concentration and nature of network-modifying (NWM) ions, (3) the openness of the structure, determined, again, by the concentration of NWM ions, and…

…with oxygen atoms, are called network formers. Chemical species such as sodium and calcium, which do not bond directly to the network but which simply sit (in ionic form) within its interstitial holes, are called network modifiers.