Electronic structure and stabilization of C$_{60}$ fullerenes encapsulating actinide atom

The geometry optimization of the neutral molecules An@C$_{60}$ (An = Th - Md) was carried out using the DFT based Dmol$^{3}$ method. In order to perform calculations for these complexes' electronic structures, the fully relativistic discrete variational method (RDV) was used. Two types of stable position of metal atom inside the C$_{60}$ cage were obtained. The most stable non-central positions are favored over the position of actinide in the fullerene center for all An@C$_{60}$ complexes. Systems containing light actinides have considerable energetic stability, which is noticeably greater than that of corresponding exohedral and “networked” complexes. The 5f-orbitals' contribution to chemical bonding was found to be noticeably less than that of the 6d-states, even for the complexes at the beginning of An@C$_{60}$ row. The effective charges on the actinide atoms were calculated using integral scheme incorporated in RDV and Hirshfeld procedure of DMol$^{3}$ code.