Electronic structures of thorium and protactinium halide clusters of [ThX 8] 4− type

Abstract

The electronic structures of ThX 4:Pa 4+ (X ≡ Cl, Br) doped crystals are obtained through MS-Xα computation of ThX 8 4− and PaX 8 4− cluster models. The incidence of the Watson sphere charge on the Rydberg-like Pa 6d MOs is discussed. The use of an effective spin-orbit operator gives f-f and f-d optical transition diagrams which, in addition to the theoretical XPS spectrum, agree quite well with the experimental data obtained from optical measurements on single crystals and doped materials at 4.2 K.