Figure 3
(a) The 2T23T2 chain of (SiO4)4− tetrahedra in amphibole-supergroup minerals with a repeat unit that contains four tetrahedra; (b) the corresponding 2V23V2 chain graph with a repeat unit that contains four vertices; (c) another 2V23V2 chain graph that is non-isomorphic (topologically different) with the chain graph in (b). |