Materials Data on Na3AlF6 by Materials Project

Abstract

Na3AlF6 crystallizes in the monoclinic P2_1/c space group. The structure is three-dimensional. there are two inequivalent Na1+ sites. In the first Na1+ site, Na1+ is bonded in a 8-coordinate geometry to eight F1- atoms. There are a spread of Na–F bond distances ranging from 2.31–2.90 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 31–38°. There are two shorter (2.26 Å) and four longer (2.32 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 31–38°. There is two shorter (1.83 Å) and four longer (1.84 Å) Al–F bond length. There are three inequivalent F1- sites. In the first F1- site, F1- is bonded in a 1-coordinate geometry to four Na1+ and one Al3+ atom. In the second F1- site, F1- is bonded in a 5-coordinate geometry to four Na1+ and one Al3+ atom. In the third F1- site, F1- is bonded in a 4-coordinate geometry to three Na1+ and one Al3+ atom.