Materials Data on Ba3GeI2 by Materials Project
Ba3GeI2 is Caswellsilverite-like structured and crystallizes in the orthorhombic Fddd space group. The structure is three-dimensional. there are two inequivalent Ba sites. In the first Ba site, Ba is bonded to two equivalent Ge and four I atoms to form a mixture of corner and edge-sharing BaGe2I4 octahedra. The corner-sharing octahedra tilt angles range from 4–8°. Both Ba–Ge bond lengths are 3.30 Å. There are two shorter (3.59 Å) and two longer (3.77 Å) Ba–I bond lengths. In the second Ba site, Ba is bonded to two equivalent Ge and four I atoms to form a mixture of corner and edge-sharing BaGe2I4 octahedra. The corner-sharing octahedra tilt angles range from 6–12°. There are one shorter (3.29 Å) and one longer (3.31 Å) Ba–Ge bond lengths. There are a spread of Ba–I bond distances ranging from 3.66–3.86 Å. Ge is bonded to six Ba atoms to form GeBa6 octahedra that share corners with six IBa6 octahedra, edges with three equivalent GeBa6 octahedra, and edges with nine IBa6 octahedra. The corner-sharing octahedra tilt angles range from 9–12°. There are two inequivalent I sites. In the first I site, I is bonded to six Ba atoms to form IBa6 octahedra that share corners with two equivalent IBa6 octahedra, corners with four equivalent GeBa6 octahedra, edges with four equivalent GeBa6 octahedra, and edges with eight IBa6 octahedra. The corner-sharing octahedra tilt angles range from 11–12°. In the second I site, I is bonded to six Ba atoms to form IBa6 octahedra that share corners with two equivalent GeBa6 octahedra, corners with four IBa6 octahedra, edges with five equivalent GeBa6 octahedra, and edges with seven IBa6 octahedra. The corner-sharing octahedra tilt angles range from 9–13°.