A central issue of f-electron metals is the importance and description of hybridization between the f and conduction electrons. The strength of the hybridization controls the general nature of the behavior:1,2 strong hybridization leads to purely itinerant behavior with properties similar to those of the transition metals, weak hybridization leads to narrow band behavior which is manifested in mixed valence, heavy fermion and Kondo lattice behavior as the hybridization decreases, and in the limit of zero hybridization the f-electron localizes leading to a well defined moment and magnetic order at low temperature. Although band theory provides a full description of hybridization for the itinerant3 and, to a certain extent, mixed valence4 and heavy fermion5,6 metals, the precise nature and description of hybridization near the local end of the spectrum is not well understood.