Ammonium Polyuranates: Old Dog, New Structural Tricks.

The crystal structure of ammonium polyuranates has been investigated. Powder X-ray diffraction (PXRD) has been employed to define single-phase samples within a series of synthesized compounds, which are further characterized by elemental analysis to ascertain the stoichiometry, revealing compositions of and . Analysis using extended X-ray absorption fine structure and vibrational spectroscopy has elucidated that both and possess a local structure similar to the metaschoepite─layered U(VI) oxohydroxide UO·2HO, but with HO and NH groups in the interlayers.