Materials Data on Sr2CaI6 by Materials Project

Abstract

Sr2CaI6 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 four equivalent SrI6 octahedra, corners with four equivalent CaI6 octahedra, and edges with two equivalent SrI6 octahedra. The corner-sharing octahedra tilt angles range from 48–55°. There are a spread of Sr–I bond distances ranging from 3.29–3.33 Å. Ca2+ is bonded to six I1- atoms to form CaI6 octahedra that share corners with eight equivalent SrI6 octahedra and edges with two equivalent CaI6 octahedra. The corner-sharing octahedra tilt angles range from 50–55°. There are a spread of Ca–I bond distances ranging from 3.14–3.20 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 two equivalent Sr2+ and one Ca2+ atom. In the third I1- site, I1- is bonded in a distorted trigonal planar geometry to three equivalent Sr2+ atoms.