CRYSTAL-FIELD AND MAGNETISM OF RGA2 (R = CE, ER) COMPOUNDS DERIVED FROM DENSITY-FUNCTIONAL CALCULATIONS

Density-functional electronic structure calculations for RGa2 intermet allic compounds were performed using the local density approximation. The 4f states were assumed localized with occupation one (CeGa2) and e leven (ErCa2) and treated in the framework of self-interaction-correct ed density functional theory. Crystal-held parameters were obtained fo r the 4f-states. These parameters were used for calculations with a mi croscopic single-ion model Hamiltonian. Our approach with no free-fit parameters is shown to provide reasonable results for the anisotropy o f the susceptibility and for the field dependence of the magnetic mome nts. For ErGa2, the shape of inelastic neutron spectra is predicted. ( C) 1997 Elsevier Science B.V. All rights reserved.