Materials Data on SrCaI4 by Materials Project

Abstract

SrCaI4 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 four equivalent SrI6 octahedra, corners with six equivalent CaI6 octahedra, and an edgeedge with one CaI6 octahedra. The corner-sharing octahedra tilt angles range from 46–55°. There are a spread of Sr–I bond distances ranging from 3.30–3.36 Å. Ca2+ is bonded to six I1- atoms to form CaI6 octahedra that share corners with six equivalent SrI6 octahedra, an edgeedge with one SrI6 octahedra, and edges with two equivalent CaI6 octahedra. The corner-sharing octahedra tilt angles range from 48–55°. There are a spread of Ca–I bond distances ranging from 3.14–3.16 Å. There are four inequivalent I1- sites. In the first I1- site, I1- is bonded in a distorted trigonal planar geometry to two equivalent Sr2+ and one Ca2+ atom. 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 equivalent Ca2+ atoms. In the fourth I1- site, I1- is bonded in a distorted trigonal planar geometry to two equivalent Sr2+ and one Ca2+ atom.