Materials Data on Sr2CaI6 by Materials Project

Abstract

Sr2CaI6 is Rutile-derived structured and crystallizes in the tetragonal P4_2/mnm 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, an edgeedge with one SrI6 octahedra, and an edgeedge with one CaI6 octahedra. The corner-sharing octahedra tilt angles range from 46–52°. There are four shorter (3.30 Å) and two longer (3.32 Å) Sr–I bond lengths. Ca2+ is bonded to six I1- atoms to form CaI6 octahedra that share corners with eight equivalent SrI6 octahedra and edges with two equivalent SrI6 octahedra. The corner-sharing octahedra tilt angles range from 46–48°. There are four shorter (3.15 Å) and two longer (3.19 Å) Ca–I bond lengths. There are two 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 two equivalent Sr2+ and one Ca2+ atom.