We report nonresonant inelastic x-ray scattering from the semicore $5d$ levels of several actinide compounds. Dipole-forbidden, high-multipole features form a rich bound-state spectrum dependent on valence electron configuration and spin-orbit and Coulomb interactions. Cross-material comparisons, together with the anomalously high Coulomb screening required for agreement between atomic-multiplet theory and experiment, demonstrate sensitivity to the neighboring electronic environment, such as is needed to address longstanding questions of electronic localization and bonding in $5f$ compounds.

• Received 6 January 2010

DOI:https://doi.org/10.1103/PhysRevB.81.193104