Interband structure and the role of the 5f electronic states of thorium: An optical investigation

The optical properties of crystalline thorium have been determined between 0.2 and 8 eV. The reflectivity and interband conductivity are seen to be rich in structures, some of which can be identified as arising from d to d interband transitions and others which must involve hybridized 5f final states. Strong structure previously reported near 4 eV is shown to be an artifact. Comparisons are made with existing band calculations, and tentative interpretations are suggested