Materials Data on Ba2Ca7I18 by Materials Project
Ba2Ca7I18 crystallizes in the triclinic P-1 space group. The structure is three-dimensional. Ba2+ is bonded in a 7-coordinate geometry to seven I1- atoms. There are a spread of Ba–I bond distances ranging from 3.52–4.23 Å. There are four inequivalent Ca2+ sites. In the first Ca2+ site, Ca2+ is bonded to six I1- atoms to form a mixture of edge and corner-sharing CaI6 octahedra. The corner-sharing octahedra tilt angles range from 50–62°. There are a spread of Ca–I bond distances ranging from 3.08–3.28 Å. In the second Ca2+ site, Ca2+ is bonded to six I1- atoms to form a mixture of edge and corner-sharing CaI6 octahedra. The corner-sharing octahedra tilt angles range from 57–60°. There are a spread of Ca–I bond distances ranging from 3.12–3.20 Å. In the third Ca2+ site, Ca2+ is bonded to six I1- atoms to form a mixture of edge and corner-sharing CaI6 octahedra. The corner-sharing octahedra tilt angles range from 53–58°. There are a spread of Ca–I bond distances ranging from 3.11–3.23 Å. In the fourth Ca2+ site, Ca2+ is bonded to six I1- atoms to form a mixture of edge and corner-sharing CaI6 octahedra. The corner-sharing octahedra tilt angles range from 50–62°. There are a spread of Ca–I bond distances ranging from 3.07–3.25 Å. There are nine inequivalent I1- sites. In the first I1- site, I1- is bonded in a distorted bent 120 degrees geometry to one Ba2+ and two Ca2+ atoms. In the second I1- site, I1- is bonded in a distorted trigonal non-coplanar geometry to one Ba2+ and two Ca2+ atoms. In the third I1- site, I1- is bonded in a distorted trigonal non-coplanar geometry to one Ba2+ and two Ca2+ atoms. In the fourth I1- site, I1- is bonded in a distorted trigonal planar geometry to three Ca2+ atoms. In the fifth I1- site, I1- is bonded in a 3-coordinate geometry to three Ca2+ atoms. In the sixth I1- site, I1- is bonded in a 3-coordinate geometry to one Ba2+ and two Ca2+ atoms. In the seventh I1- site, I1- is bonded in an L-shaped geometry to two Ca2+ atoms. In the eighth I1- site, I1- is bonded in a 3-coordinate geometry to one Ba2+ and three Ca2+ atoms. In the ninth I1- site, I1- is bonded to two equivalent Ba2+ and two Ca2+ atoms to form a mixture of distorted edge and corner-sharing IBa2Ca2 trigonal pyramids.