Structural relations of UO2, isometric PbUO4 and orthorhombic PbUO4

Isomeric and orthorhombic PbUO/sub 4/ was synthesized by heatirg U/sub 3/ O/sub 8/ wiin PbO and excess sheet lead in water at 230 to 290 deg C. Both substances contain U/sup 6+/ and the formula is more properly written Pb(UO/sub 2/ )O/sub 2/. The isometric polymorph is isostructural with UO/sub 2/ with A/sub 0/ = 5.800 plus or minus 0.002 A. Orthorhombic PbUO/sub 4/ is isostructural with DaUO/sub 4/ with A/sub 0/ = 5.528, b/sub 0/ = 7.952, and c/sub 0/ = 8.150 A Tables of spectral data are included. (D.E.B.)