Crystal-Field Splitting in Kondo Systems

The mixing interaction in the Anderson model of local moments in metals $V_{\mathrm{k}\sigma ,m}$ depends on the orbital state $m$ of the local electron. We have taken into account this anisotropy and find that, quite aside from other mechanisms, e.g., crystalline electric fields, the mixing alone can account for the magnitudes of the splitting and linewidths of the local $f$ states observed in Kondo-type systems, e.g., heavy-fermion and mixed-valence compounds.