Materials Data on UO3 by Materials Project

Abstract

UO3 crystallizes in the orthorhombic Fddd space group. The structure is three-dimensional. there are two inequivalent U6+ sites. In the first U6+ site, U6+ is bonded to six O2- atoms to form distorted corner-sharing UO6 pentagonal pyramids. The corner-sharing octahedra tilt angles range from 25–53°. There are two shorter (1.82 Å) and four longer (2.35 Å) U–O bond lengths. In the second U6+ site, U6+ is bonded to six O2- atoms to form a mixture of edge and corner-sharing UO6 octahedra. There are a spread of U–O bond distances ranging from 1.91–2.24 Å. There are three inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted bent 150 degrees geometry to two U6+ atoms. In the second O2- site, O2- is bonded in a distorted trigonal planar geometry to three U6+ atoms. In the third O2- site, O2- is bonded in a single-bond geometry to one U6+ atom.