Sr2CaI6 is Rutile-derived structured and crystallizes in the orthorhombic Pbcn space group. Sr(1) is bonded to one I(1), two equivalent I(2), and three equivalent I(3) atoms to form SrI6 octahedra that share corners with four equivalent Sr(1)I6 octahedra, corners with four equivalent Ca(1)I6 octahedra, and edges with two equivalent Sr(1)I6 octahedra. The corner-sharing octahedral tilt angles range from 48-55°. Ca(1) is bonded to two equivalent I(2) and four equivalent I(1) atoms to form CaI6 octahedra that share corners with eight equivalent Sr(1)I6 octahedra and edges with two equivalent Ca(1)I6 octahedra. The corner-sharing octahedral tilt angles range from 50-55°. There are three inequivalent I sites. In the first I site, I(1) is bonded in a trigonal planar geometry to one Sr(1) and two equivalent Ca(1) atoms. In the second I site, I(2) is bonded in a distorted trigonal planar geometry to two equivalent Sr(1) and one Ca(1) atom. In the third I site, I(3) is bonded in a distorted trigonal planar geometry to three equivalent Sr(1) atoms.
Sr2CaI6 is Rutile-derived structured and crystallizes in the orthorhombic Pbcn space group. Sr(1) is bonded to one I(1), two equivalent I(2), and three equivalent I(3) atoms to form SrI6 octahedra that share corners with four equivalent Sr(1)I6 octahedra, corners with four equivalent Ca(1)I6 octahedra, and edges with two equivalent Sr(1)I6 octahedra. The corner-sharing octahedral tilt angles range from 48-55°. The Sr(1)-I(1) bond length is 3.30 Å. There is one shorter (3.32 Å) and one longer (3.33 Å) Sr(1)-I(2) bond length. There are a spread of Sr(1)-I(3) bond distances ranging from 3.29-3.31 Å. Ca(1) is bonded to two equivalent I(2) and four equivalent I(1) atoms to form CaI6 octahedra that share corners with eight equivalent Sr(1)I6 octahedra and edges with two equivalent Ca(1)I6 octahedra. The corner-sharing octahedral tilt angles range from 50-55°. Both Ca(1)-I(2) bond lengths are 3.19 Å. There are two shorter (3.14 Å) and two longer (3.20 Å) Ca(1)-I(1) bond lengths. There are three inequivalent I sites. In the first I site, I(1) is bonded in a trigonal planar geometry to one Sr(1) and two equivalent Ca(1) atoms. In the second I site, I(2) is bonded in a distorted trigonal planar geometry to two equivalent Sr(1) and one Ca(1) atom. In the third I site, I(3) is bonded in a distorted trigonal planar geometry to three equivalent Sr(1) atoms.