For PuO 2 , there have been CF and LF 38 studies. Both types of studies assume an oxidation state of Pu(IV) and an open-shell occupation of 5f and have correctly given the symmetry of the ground state as Γ 1 . This state is non-degenerate and does not have a permanent magnetic moment, consistent with the known magnetic properties of PuO 2 . CF theory predicts the symmetry of the excited multiplet as Γ 4 with an excitation energy of 0.115 eV from the Γ 1 ground state multiplet; these results for the symmetry and energy of the dipole allowed excited multiplet are consistent with experiments and support the assignment of the Pu oxidation state as Pu(IV). In addition, our previous ab initio analysis of the XANES spectrum is consistent with the experiment and provides additional information about the character of the open-shell orbitals. Note that it is essential that the initial state of PuO 2 contains 4 valence electrons in order to have the total symmetry of Γ 1 , which is required to explain the magnetic properties as well as the XANES. An assignment of the open shell of PuO 2 as Pu(III) or 5f is therefore inconsistent both with the analyses and interpretations of CF and LF theories as well as with a large body of experimental data.