Materials Data on SrCa2I6 by Materials Project

Abstract

SrCa2I6 is zeta iron carbide-derived structured and crystallizes in the orthorhombic Pbcn space group. The structure is three-dimensional. Sr2+ is bonded to six I1- atoms to form SrI6 octahedra that share corners with eight CaI6 octahedra and edges with two equivalent CaI6 octahedra. The corner-sharing octahedra tilt angles range from 51–54°. There are two shorter (3.29 Å) and four longer (3.31 Å) Sr–I bond lengths. There are two inequivalent Ca2+ sites. In the first Ca2+ site, Ca2+ is bonded to six I1- atoms to form CaI6 octahedra that share corners with two equivalent CaI6 octahedra, corners with six equivalent SrI6 octahedra, and edges with two equivalent CaI6 octahedra. The corner-sharing octahedra tilt angles range from 48–53°. There are a spread of Ca–I bond distances ranging from 3.14–3.19 Å. In the second Ca2+ site, Ca2+ is bonded to six I1- atoms to form CaI6 octahedra that share corners with two equivalent SrI6 octahedra, corners with six CaI6 octahedra, and edges with two equivalent SrI6 octahedra. The corner-sharing octahedra tilt angles range from 48–54°. There are a spread of Ca–I bond distances ranging from 3.16–3.18 Å. There are three inequivalent I1- sites. In the first I1- site, I1- is bonded in a distorted trigonal planar geometry to one Sr2+ and two equivalent Ca2+ atoms. In the second I1- site, I1- is bonded in a distorted trigonal planar geometry to one Sr2+ and two equivalent Ca2+ atoms. In the third I1- site, I1- is bonded in a distorted trigonal planar geometry to one Sr2+ and two Ca2+ atoms.