Materials Data on Na2UF6 by Materials Project

Abstract

Na2UF6 is alpha bismuth trifluoride-derived structured and crystallizes in the monoclinic C2/m space group. The structure is three-dimensional. Na1+ is bonded in a body-centered cubic geometry to eight F1- atoms. There are a spread of Na–F bond distances ranging from 2.43–2.51 Å. U4+ is bonded in a body-centered cubic geometry to eight F1- atoms. There are four shorter (2.21 Å) and four longer (2.40 Å) U–F bond lengths. There are two inequivalent F1- sites. In the first F1- site, F1- is bonded to two equivalent Na1+ and two equivalent U4+ atoms to form a mixture of edge and corner-sharing FNa2U2 tetrahedra. In the second F1- site, F1- is bonded to three equivalent Na1+ and one U4+ atom to form a mixture of edge and corner-sharing FNa3U tetrahedra.