A Reassessment of 5f Occupation in Plutonium

A detailed spectroscopic simulation of the original Pu N4,5 and O4,5 X-Ray Absorption Spectroscopy (XAS) has been performed. Additionally, a fundamental flaw in the Electron Energy Loss Spectroscopy (EELS) measurement has been corrected. Thus, the determination of the 5f occupation (n) in elemental Pu has been re-evaluated with the result that n = 5.0 +/- 0.1 for alphaPu and n = 4.9 +/- 0.2 for deltaPu. These values are significantly lower than the value of ~5.5 that was propagated earlier.