Materials Data on Na3AlF6 by Materials Project

Abstract

Na3AlF6 crystallizes in the orthorhombic Immm space group. The structure is three-dimensional. there are two inequivalent Na1+ sites. In the first Na1+ site, Na1+ is bonded in a 12-coordinate geometry to twelve F1- atoms. There are a spread of Na–F bond distances ranging from 2.62–3.09 Å. In the second Na1+ site, Na1+ is bonded to six F1- atoms to form NaF6 octahedra that share corners with six equivalent AlF6 octahedra. The corner-sharing octahedra tilt angles range from 0–4°. There are four shorter (2.20 Å) and two longer (2.21 Å) Na–F bond lengths. Al3+ is bonded to six F1- atoms to form AlF6 octahedra that share corners with six equivalent NaF6 octahedra. The corner-sharing octahedra tilt angles range from 0–4°. All Al–F bond lengths are 1.82 Å. There are two inequivalent F1- sites. In the first F1- site, F1- is bonded in a 4-coordinate geometry to five Na1+ and one Al3+ atom. In the second F1- site, F1- is bonded in a distorted linear geometry to five Na1+ and one Al3+ atom.