Materials Data on Na2UO4 by Materials Project

Abstract

Na2UO4 crystallizes in the orthorhombic Pbam space group. The structure is three-dimensional. Na1+ is bonded in a 7-coordinate geometry to seven O2- atoms. There are a spread of Na–O bond distances ranging from 2.39–2.76 Å. U6+ is bonded to six O2- atoms to form edge-sharing UO6 octahedra. There are two shorter (1.94 Å) and four longer (2.20 Å) U–O bond lengths. There are two inequivalent O2- sites. In the first O2- site, O2- is bonded in a 5-coordinate geometry to four equivalent Na1+ and one U6+ atom. In the second O2- site, O2- is bonded to three equivalent Na1+ and two equivalent U6+ atoms to form a mixture of distorted corner and edge-sharing ONa3U2 trigonal bipyramids.