1ST-PRINCIPLES STUDY OF THE MAGNETIZATION DENSITY IN CEFE2

We present first-principles calculations of the magnetization density and its resolution into spin and orbital moments in CeFe2. The calculations do not rely on any shape assumptions concerning the density or potential and verify that the total moment on the Ce and Fe sites are coupled antiparallel. This is due to the fact that the Fe and Ce spin moments are coupled antiparallel and that the orbital moment on the Ce site is smaller than the spin moment. We argue that this is in sharp contrast to the expected behavior for a 4f local moment system, where essentially the free-ion behavior of the Ce magnetism is expected, with an orbital moment larger and antiparallel to the spin moment. The recent suggestion of a large nonspherical moment density in CeFe2 is specifically addressed and the calculations are found to support such a behavior. The calculated individual moments are approximately 50% larger than the moments deduced from neutron-scattering experiments.