ABSTRACT
A metal is a lot more than a lattice of atoms in their electronic ground states. In the atomic lattice state, for many metals the only bond formation would be due to van der Waals-induced dipole interactions. Those interactions are hardly up to the task of stabilizing a solid. Bonding is a matter of electronic overlap between singly occupied or vacant atomic functions to form the delocalized one-electron bonds that characterize the valence level of metals. These massively degenerate wave functions arise from singly occupied atomic functions that combine to form densely packed (in the energy coordinate) bands of molecular wave functions. In atoms where there are no unpaired electrons at the valence level, one or more electrons must be promoted* to a higher energy orbital to permit bond formation. Bonding in metals has been traditionally studied under the title of band theory, where the focus was on delocalization and conduction properties. Here, we will make an effort to introduce both the bonding and the electron delocalization aspects of the problem.
