Materials Data on NaU2F9 by Materials Project

Abstract

NaU2F9 crystallizes in the monoclinic Cc space group. The structure is three-dimensional. Na1+ is bonded in a 6-coordinate geometry to six F1- atoms. There are a spread of Na–F bond distances ranging from 2.34–2.44 Å. There are two inequivalent U4+ sites. In the first U4+ site, U4+ is bonded in a 9-coordinate geometry to nine F1- atoms. There are a spread of U–F bond distances ranging from 2.26–2.43 Å. In the second U4+ site, U4+ is bonded in a 9-coordinate geometry to nine F1- atoms. There are a spread of U–F bond distances ranging from 2.25–2.41 Å. There are nine inequivalent F1- sites. In the first F1- site, F1- is bonded in a linear geometry to two U4+ atoms. In the second F1- site, F1- is bonded in a distorted trigonal non-coplanar geometry to one Na1+ and two U4+ atoms. In the third F1- site, F1- is bonded in a distorted trigonal planar geometry to one Na1+ and two U4+ atoms. In the fourth F1- site, F1- is bonded in a distorted trigonal non-coplanar geometry to one Na1+ and two U4+ atoms. In the fifth F1- site, F1- is bonded in a distorted trigonal non-coplanar geometry to one Na1+ and two U4+ atoms. In the sixth F1- site, F1- is bonded in a bent 150 degrees geometry to two equivalent U4+ atoms. In the seventh F1- site, F1- is bonded in a bent 150 degrees geometry to two equivalent U4+ atoms. In the eighth F1- site, F1- is bonded in a 3-coordinate geometry to one Na1+ and two U4+ atoms. In the ninth F1- site, F1- is bonded in a distorted trigonal non-coplanar geometry to one Na1+ and two U4+ atoms.