Materials Data on CsAlCuF6 by Materials Project

Abstract

CsCuAlF6 crystallizes in the orthorhombic Pnma space group. The structure is three-dimensional. Cs1+ is bonded in a 5-coordinate geometry to five F1- atoms. There are a spread of Cs–F bond distances ranging from 3.11–3.15 Å. Cu2+ is bonded to six F1- atoms to form CuF6 octahedra that share corners with two equivalent CuF6 octahedra and corners with four equivalent AlF6 octahedra. The corner-sharing octahedra tilt angles range from 44–46°. There are a spread of Cu–F bond distances ranging from 1.96–2.12 Å. Al3+ is bonded to six F1- atoms to form AlF6 octahedra that share corners with two equivalent AlF6 octahedra and corners with four equivalent CuF6 octahedra. The corner-sharing octahedra tilt angles range from 29–45°. There are a spread of Al–F bond distances ranging from 1.81–1.86 Å. There are four inequivalent F1- sites. In the first F1- site, F1- is bonded in a 2-coordinate geometry to one Cs1+ and two equivalent Cu2+ 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 2-coordinate geometry to one Cs1+, one Cu2+, and one Al3+ atom. In the fourth F1- site, F1- is bonded in a 2-coordinate geometry to one Cs1+, one Cu2+, and one Al3+ atom.