Molecules Meet Solids: From Wade–Mingos Clusters to Intermetalloid Clusters

The common feature of molecular deltahedral borane clusters, molecules with a set of multiple bonds and metals is their electron deficiency, and they are all connected with the term “electron delocalization,” although with different meanings. The atomic and electronic structure of atom clusters is right between that of molecules and the extended bulk, and thus these clusters meet at the interface of molecules and solids.