Materials Data on SrCa2I6 by Materials Project

Abstract

SrCa2I6 is zeta iron carbide-derived structured and crystallizes in the monoclinic P2_1/c 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, an edgeedge with one SrI6 octahedra, and an edgeedge with one CaI6 octahedra. The corner-sharing octahedra tilt angles range from 48–59°. There are a spread of Sr–I bond distances ranging from 3.29–3.31 Å. 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 SrI6 octahedra, corners with six CaI6 octahedra, an edgeedge with one SrI6 octahedra, and an edgeedge with one CaI6 octahedra. The corner-sharing octahedra tilt angles range from 46–59°. There are a spread of Ca–I bond distances ranging from 3.12–3.22 Å. In the second 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 CaI6 octahedra. The corner-sharing octahedra tilt angles range from 48–58°. There are a spread of Ca–I bond distances ranging from 3.14–3.19 Å. There are six 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 Ca2+ atoms. In the third I1- site, I1- is bonded in a distorted trigonal planar geometry to two equivalent Sr2+ and one Ca2+ atom. In the fourth I1- site, I1- is bonded in a distorted trigonal planar geometry to one Sr2+ and two equivalent Ca2+ atoms. In the fifth I1- site, I1- is bonded in a distorted trigonal planar geometry to one Sr2+ and two Ca2+ atoms. In the sixth I1- site, I1- is bonded in a distorted trigonal planar geometry to three Ca2+ atoms.