Materials Data on BaSr2I6 by Materials Project

Abstract

BaSr2I6 is zeta iron carbide-derived structured and crystallizes in the trigonal P321 space group. The structure is three-dimensional. there are two inequivalent Ba2+ sites. In the first Ba2+ site, Ba2+ is bonded to six I1- atoms to form BaI6 octahedra that share corners with six equivalent SrI6 octahedra and edges with three equivalent SrI6 octahedra. The corner-sharing octahedra tilt angles range from 55–57°. There are three shorter (3.46 Å) and three longer (3.47 Å) Ba–I bond lengths. In the second Ba2+ site, Ba2+ is bonded to six equivalent I1- atoms to form BaI6 octahedra that share corners with six equivalent SrI6 octahedra and edges with three equivalent SrI6 octahedra. The corner-sharing octahedral tilt angles are 60°. All Ba–I bond lengths are 3.47 Å. There are two inequivalent Sr2+ sites. In the first Sr2+ site, Sr2+ is bonded to six I1- atoms to form SrI6 octahedra that share corners with four equivalent BaI6 octahedra, corners with six equivalent SrI6 octahedra, and an edgeedge with one BaI6 octahedra. The corner-sharing octahedra tilt angles range from 46–57°. There are two shorter (3.33 Å) and four longer (3.35 Å) Sr–I bond lengths. In the second Sr2+ site, Sr2+ is bonded to six I1- atoms to form SrI6 octahedra that share corners with two equivalent BaI6 octahedra, corners with six equivalent SrI6 octahedra, and edges with two equivalent BaI6 octahedra. The corner-sharing octahedra tilt angles range from 46–60°. There are a spread of Sr–I bond distances ranging from 3.32–3.34 Å. There are three inequivalent I1- sites. In the first I1- site, I1- is bonded in a distorted trigonal planar geometry to one Ba2+ and two Sr2+ atoms. In the second I1- site, I1- is bonded in a distorted trigonal planar geometry to one Ba2+ and two Sr2+ atoms. In the third I1- site, I1- is bonded in a distorted trigonal planar geometry to one Ba2+ and two Sr2+ atoms.