DOI: 10.17188/1267648
title: Materials Data on Ba4Al3Cu2F21 by Materials Project

description: Ba4Cu2Al3F21 crystallizes in the orthorhombic P2_12_12_1 space group. The structure is three-dimensional. there are four inequivalent Ba2+ sites. In the first Ba2+ site, Ba2+ is bonded in a 11-coordinate geometry to eleven F1- atoms. There are a spread of Ba–F bond distances ranging from 2.70–3.23 Å. In the second Ba2+ site, Ba2+ is bonded in a 11-coordinate geometry to eleven F1- atoms. There are a spread of Ba–F bond distances ranging from 2.66–3.14 Å. In the third Ba2+ site, Ba2+ is bonded in a 11-coordinate geometry to eleven F1- atoms. There are a spread of Ba–F bond distances ranging from 2.68–3.09 Å. In the fourth Ba2+ site, Ba2+ is bonded in a 12-coordinate geometry to twelve F1- atoms. There are a spread of Ba–F bond distances ranging from 2.78–3.27 Å. There are two inequivalent Cu2+ sites. In the first Cu2+ site, Cu2+ is bonded to six F1- atoms to form distorted CuF6 octahedra that share corners with two equivalent AlF6 octahedra and edges with two equivalent CuF6 octahedra. The corner-sharing octahedra tilt angles range from 52–60°. There are a spread of Cu–F bond distances ranging from 1.89–2.49 Å. In the second Cu2+ site, Cu2+ is bonded to six F1- atoms to form distorted CuF6 octahedra that share corners with two equivalent AlF6 octahedra and edges with two equivalent CuF6 octahedra. The corner-sharing octahedra tilt angles range from 54–56°. There are a spread of Cu–F bond distances ranging from 1.91–2.44 Å. There are three inequivalent Al3+ sites. In the first Al3+ site, Al3+ is bonded to six F1- atoms to form corner-sharing AlF6 octahedra. The corner-sharing octahedra tilt angles range from 24–27°. There are a spread of Al–F bond distances ranging from 1.78–1.90 Å. In the second Al3+ site, Al3+ is bonded to six F1- atoms to form corner-sharing AlF6 octahedra. The corner-sharing octahedra tilt angles range from 24–27°. There are a spread of Al–F bond distances ranging from 1.79–1.91 Å. In the third Al3+ site, Al3+ is bonded to six F1- atoms to form AlF6 octahedra that share corners with four CuF6 octahedra. The corner-sharing octahedra tilt angles range from 52–60°. There are a spread of Al–F bond distances ranging from 1.80–1.88 Å. There are twenty-one inequivalent F1- sites. In the first F1- site, F1- is bonded in a 1-coordinate geometry to two Ba2+, one Cu2+, and one Al3+ atom. In the second F1- site, F1- is bonded in a bent 120 degrees geometry to one Ba2+, one Cu2+, and one Al3+ atom. In the third F1- site, F1- is bonded in a bent 150 degrees geometry to one Ba2+ and two Al3+ atoms. In the fourth F1- site, F1- is bonded in a 1-coordinate geometry to two Ba2+ and two Cu2+ atoms. In the fifth F1- site, F1- is bonded in a distorted single-bond geometry to two Ba2+ and one Cu2+ atom. In the sixth F1- site, F1- is bonded in a distorted single-bond geometry to two equivalent Ba2+ and one Al3+ atom. In the seventh F1- site, F1- is bonded in a distorted single-bond geometry to two Ba2+ and one Al3+ atom. In the eighth F1- site, F1- is bonded in a bent 150 degrees geometry to one Ba2+ and two Al3+ atoms. In the ninth F1- site, F1- is bonded in a distorted single-bond geometry to three Ba2+ and one Al3+ atom. In the tenth F1- site, F1- is bonded in a distorted single-bond geometry to three equivalent Ba2+ and one Al3+ atom. In the eleventh F1- site, F1- is bonded in a distorted trigonal planar geometry to two equivalent Ba2+ and one Cu2+ atom. In the twelfth F1- site, F1- is bonded in a distorted single-bond geometry to two Ba2+ and one Al3+ atom. In the thirteenth F1- site, F1- is bonded in a distorted water-like geometry to two equivalent Ba2+ and two Cu2+ atoms. In the fourteenth F1- site, F1- is bonded in a distorted single-bond geometry to three Ba2+ and one Al3+ atom. In the fifteenth F1- site, F1- is bonded in a distorted single-bond geometry to three equivalent Ba2+ and one Al3+ atom. In the sixteenth F1- site, F1- is bonded in a distorted single-bond geometry to three Ba2+ and one Al3+ atom. In the seventeenth F1- site, F1- is bonded in a distorted single-bond geometry to three Ba2+ and one Al3+ atom. In the eighteenth F1- site, F1- is bonded in a distorted single-bond geometry to two equivalent Ba2+ and one Al3+ atom. In the nineteenth F1- site, F1- is bonded in a distorted water-like geometry to two Ba2+ and two Cu2+ atoms. In the twentieth F1- site, F1- is bonded in a distorted single-bond geometry to three equivalent Ba2+ and one Al3+ atom. In the twenty-first F1- site, F1- is bonded in a 1-coordinate geometry to one Ba2+, two Cu2+, and one Al3+ atom.