NPA was also performed based on the scalar relativistic CASSCF calculation of the ground state, yielding 1.25 excess population of the 5f shell (0.96 from 5f') hence essentially the same NPA results as the spin-unrestricted HF (UHF) calculation. This result is not too surprising. The active space would have to be much larger to be able to generate an appreciable fraction of the dynamic electron correlation in the wavefunction and the associated density matrix on which the NPA is based. Therefore, MC-WFT calculations with attainable active spaces and density matrices that are not explicitly corrected for the dynamic correlation will exhibit a similar 'negative DE' as HF calculations. In other words, n f determined by HF and MC-WFT is too small because the LM donation is underestimated as a consequence of the lack of dynamic correlation and the associated localization error. There is nonetheless more than a full electron donated to the 5f shell, if the diffuse regions of the f-shell are included in the electron count. Without the diffuse f-shell regions, that is, discounting the 5f' occupations (Table ) the HF and MC-WFT calculations give much less than one electron of aggregate donation into 5f. At the opposite extreme of the DE scale is the non-hybrid DFT calculation (0% eX), which produces a full electron (1.02) donated into 5f proper and an additional 0.71 occupation from the diffuse regions, leading to an aggregate n f = 1.73.