Materials Data on AlCoNF6 by Materials Project

Abstract

(CoAlF6)2N2 crystallizes in the orthorhombic Imma space group. The structure is three-dimensional and consists of four ammonia molecules and one CoAlF6 framework. In the CoAlF6 framework, Co2+ is bonded to six F1- atoms to form CoF6 octahedra that share corners with two equivalent CoF6 octahedra and corners with four equivalent AlF6 octahedra. The corner-sharing octahedra tilt angles range from 40–45°. There is four shorter (1.92 Å) and two longer (1.94 Å) Co–F bond length. Al3+ is bonded to six F1- atoms to form AlF6 octahedra that share corners with two equivalent AlF6 octahedra and corners with four equivalent CoF6 octahedra. The corner-sharing octahedra tilt angles range from 34–40°. All Al–F bond lengths are 1.83 Å. There are three inequivalent F1- sites. In the first F1- site, F1- is bonded in a distorted bent 150 degrees geometry to two equivalent Co2+ atoms. In the second F1- site, F1- is bonded in a bent 150 degrees geometry to two equivalent Al3+ atoms. In the third F1- site, F1- is bonded in a bent 150 degrees geometry to one Co2+ and one Al3+ atom.