Research will be conducted on the unusual magnetic behavior exhibited by three series of correlated f-electron systems: the cerium monochalcogenides CeX (X = S, Se, Te); the uranium monopnictides UX (X = N, P, As, Sb, Bi); and, the uranium monochalcogenides. A synthesis of first-principles electronic structure calculations and a phenomenological model of orbitally- driven magnetic ordering will be employed to investigate the effect of hybridization of moderately delocalized f-electrons with band electrons on the diverse magnetic behavior of this class of systems.