Bond Lengths and An 4f Electron Energies in AnO2 (An = Cf–Lr)

Extrapolation of available experimental data for AnO₂ (An = Th, U–Bk), represented on a unified binding energy scale on which E_b(O 1s) = 529.9 eV, has been used to evaluate bond lengths and An 4f electron binding energies in AnO₂ (An = Cf–Lr). The bond lengths thus found are in qualitative agreement with results obtained in the ionic approximation, and the An 4f electron binding energies have been determined with an uncertainty of ±0.4 eV, which is an order of magnitude smaller than that in available reference values. The results obtained on the structure of the actinide dioxides are needed for relativistic calculations of valence band X-ray photoelectron spectra of AnO₂, and the An 4f electron binding energies are needed for constructing quantitative schemes of molecular orbitals in AnO₂. These data will be useful for understanding general aspects of the formation of specific features of the electronic structure and chemical bonding in the AnO₂ (An = Th–Lr) series.