Materials Data on Na2UF6 by Materials Project

Abstract

Na2UF6 crystallizes in the trigonal P321 space group. The structure is three-dimensional. Na1+ is bonded in a 9-coordinate geometry to nine F1- atoms. There are a spread of Na–F bond distances ranging from 2.34–2.89 Å. U4+ is bonded in a 9-coordinate geometry to nine F1- atoms. There are three shorter (2.25 Å) and six 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 distorted edge and corner-sharing FNa2U2 tetrahedra. In the second F1- site, F1- is bonded in a 3-coordinate geometry to four equivalent Na1+ and one U4+ atom.