Topological aspects of infinite metal clusters and superconductors

This paper summarizes the chemical bonding topology of infinite metal clusters as well as superconductors constructed from metal octahedra or metal tetrahedra. The chemical bonding topologies of discrete octahedral metal clusters can be either edge-localized (e.g., Mo6x8L64+ derivatives), face-localized (e.g., Nb6x12L62+ derivatives), or globally delocalized (e.g., Zr6mu2-CL)12ECLn-12 derivatives where E=Be, B, C, N,). Infinite fusion of metal octahedra in one, two, and three dimensions leads to metal cluster chains (e.g., Gd2CI3), metal cluster sheets (e.g., ZrCL), and bulk metals, respectively. Superconductors exhibiting relatively high critical temperatures and magnetic fields are constructed from edge-localized metal polyhedra such as the Mo6 octahedra in the ternary molybdenum chalcogenides (Chevrel phases) and Rh4 tetrahedra in the ternary lanthanide rhodium borides leading naturally to the concept of porous delocalization in such materials.