Computational insights into the lattice dynamics of Pu(IV) oxalates

Abstract

Despite its use in PuO2 production, the structure of anhydrous Pu(C2O4)2 is still not completely understood. Recently, two candidate structures for Pu(C2O4)2 were proposed via density functional theory (DFT), after which the first experimental optical vibrational spectra were reported. Here, we calculated the lattice dynamics of the candidate structures using DFT and found that the primary difference between them is the presence of a vibrational mode near 1380 cm−1 in one structure. The frequency and optical activity of this mode agree well with the published experimental results, providing strong support for this calculated structure as that of anhydrous Pu(C2O4)2.