Crystal-field and magnetism of RGa2 (R = Ce, Er) compounds derived from density-functional calculations

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