Materials Data on Ba2YF7 by Materials Project

Abstract

Ba2YF7 crystallizes in the orthorhombic Pnma space group. The structure is three-dimensional. there are two inequivalent Ba2+ sites. In the first Ba2+ site, Ba2+ is bonded to seven F1- atoms to form BaF7 pentagonal bipyramids that share corners with three equivalent YF6 octahedra, corners with two equivalent BaF7 pentagonal bipyramids, and an edgeedge with one YF6 octahedra. The corner-sharing octahedra tilt angles range from 35–57°. There are a spread of Ba–F bond distances ranging from 2.64–2.75 Å. In the second Ba2+ site, Ba2+ is bonded in a 7-coordinate geometry to seven F1- atoms. There are a spread of Ba–F bond distances ranging from 2.61–2.80 Å. Y3+ is bonded to six F1- atoms to form YF6 octahedra that share corners with three equivalent BaF7 pentagonal bipyramids and an edgeedge with one BaF7 pentagonal bipyramid. There are a spread of Y–F bond distances ranging from 2.17–2.21 Å. There are five inequivalent F1- sites. In the first F1- site, F1- is bonded in a distorted trigonal planar geometry to two Ba2+ and one Y3+ atom. In the second F1- site, F1- is bonded in a bent 150 degrees geometry to one Ba2+ and one Y3+ atom. In the third F1- site, F1- is bonded in a trigonal planar geometry to three Ba2+ atoms. In the fourth F1- site, F1- is bonded in a 3-coordinate geometry to two Ba2+ and one Y3+ atom. In the fifth F1- site, F1- is bonded in a 3-coordinate geometry to two Ba2+ and one Y3+ atom.