Development of magnetism in strongly correlated cerium systems: Non-Kondo mechanism for moment collapse

We present an nb initio-based method which gives clear insight into the int erplay between the band-f hybridization, the band-f Coulomb exchange, and t he crystal-field interactions, as the degree of 4f localization is varied a cross a series of strongly correlated cerium systems. The predictions for t he ordered magnetic moments, magnetic structure, and ordering temperatures are in excellent agreement with experiment, including the occurrence of a m oment collapse of non-Kondo origin. In contrast, spin- and orbitally polari zed nb initio density functional calculations and local density approximati on + U calculations fail to predict, even qualitatively, the trend of the u nusual magnetic properties.