Absolute evaluation of combined hybridization‐induced and RKKY‐induced two‐ion interaction in correlated electron systems

Cerium and light actinide materials have unusual properties, including suppressed crystal‐field splitting and highly anisotropic ordered magnetism, that can be understood on the basis of the Coulomb interaction between partially delocalized f electrons and the non‐f‐band electrons. In setting the absolute scale of interaction energy for materially predictive theory, it is crucial to take account of all consequences of the Coulomb interaction which contribute to the two‐ion interaction. These include both the hybridization‐induced effect (i.e., band‐f mixing effects treated by a one‐electron potential) and the RKKY‐type effect (arising from the band‐f exchange interaction) and the cross effect. The RKKY interaction, when treated fully, provides both isotropic and anisotropic contributions to the two‐ion interaction. We found the anisotropic part is similar in its angular dependence and range dependence to the hybridization‐induced effects. Therefore, the qualitative anisotropic nature of observable magneti...