Computational study of the substitution of early actinides and Ce into zirconolite

Substitutions of tetravalent early actinides (Th – Am) and Ce into the ceramic nuclear waste form zirconolite, CaZrTi2O7, have been analysed using hybrid Density Functional Theory in conjunction with Periodic Electrostatic Embedded Cluster Method. on to both Zr4+ Ca2+ sites were modelled, Fe3+ Al3+ used for charge balancing. The mean displacements a central region ions cluster indicated redox behaviour which was then confirmed through analysis spin density data. Strong correlations found between substitution energies these ratio ionic radii substituents substituted ions. Similar seen substitutions Ce4+ Pu4+ lattice. Spin data molecular M(OH)n (M = Ce, Th - Am, n 3–5) showed preference +3 oxidation state later as zirconolite clusters.