Materials Data on Na3TiF8 by Materials Project

Abstract

Na3TiF8 crystallizes in the orthorhombic Cmcm space group. The structure is three-dimensional. there are two inequivalent Na sites. In the first Na site, Na is bonded in a 4-coordinate geometry to six F atoms. There are a spread of Na–F bond distances ranging from 2.37–2.75 Å. In the second Na site, Na is bonded to six F atoms to form NaF6 octahedra that share corners with four equivalent TiF6 octahedra and edges with two equivalent NaF6 octahedra. The corner-sharing octahedra tilt angles range from 31–55°. There are a spread of Na–F bond distances ranging from 2.18–2.46 Å. Ti is bonded to six F atoms to form TiF6 octahedra that share corners with eight equivalent NaF6 octahedra. The corner-sharing octahedra tilt angles range from 31–55°. There is two shorter (1.86 Å) and four longer (1.91 Å) Ti–F bond length. There are four inequivalent F sites. In the first F site, F is bonded in a bent 150 degrees geometry to one Na and one Ti atom. In the second F site, F is bonded in a distorted trigonal planar geometry to two Na and one Ti atom. In the third F site, F is bonded in a 4-coordinate geometry to three Na and one Ti atom. In the fourth F site, F is bonded in a trigonal non-coplanar geometry to three Na atoms.