Materials Data on BaGe3O8 by Materials Project
BaGe3O8 crystallizes in the monoclinic Cc space group. The structure is three-dimensional. Ba is bonded to twelve O atoms to form BaO12 cuboctahedra that share corners with six GeO6 octahedra, edges with four equivalent BaO12 cuboctahedra, edges with six GeO6 octahedra, and faces with two GeO6 octahedra. The corner-sharing octahedra tilt angles range from 31–47°. There are a spread of Ba–O bond distances ranging from 2.88–3.13 Å. There are three inequivalent Ge sites. In the first Ge site, Ge is bonded to six O atoms to form GeO6 octahedra that share corners with four equivalent BaO12 cuboctahedra, corners with two GeO6 octahedra, edges with two equivalent BaO12 cuboctahedra, and edges with four GeO6 octahedra. The corner-sharing octahedral tilt angles are 54°. There are a spread of Ge–O bond distances ranging from 1.88–1.98 Å. In the second Ge site, Ge is bonded to six O atoms to form GeO6 octahedra that share a cornercorner with one BaO12 cuboctahedra, corners with three GeO6 octahedra, edges with two equivalent BaO12 cuboctahedra, edges with three GeO6 octahedra, and a faceface with one BaO12 cuboctahedra. The corner-sharing octahedra tilt angles range from 48–54°. There are a spread of Ge–O bond distances ranging from 1.85–2.02 Å. In the third Ge site, Ge is bonded to six O atoms to form GeO6 octahedra that share a cornercorner with one BaO12 cuboctahedra, corners with three GeO6 octahedra, edges with two equivalent BaO12 cuboctahedra, edges with three GeO6 octahedra, and a faceface with one BaO12 cuboctahedra. The corner-sharing octahedra tilt angles range from 48–54°. There are a spread of Ge–O bond distances ranging from 1.85–2.02 Å. There are eight inequivalent O sites. In the first O site, O is bonded in a distorted trigonal planar geometry to one Ba and three Ge atoms. In the second O site, O is bonded in a distorted water-like geometry to two equivalent Ba and two Ge atoms. In the third O site, O is bonded in a 4-coordinate geometry to one Ba and three Ge atoms. In the fourth O site, O is bonded in a 4-coordinate geometry to one Ba and three Ge atoms. In the fifth O site, O is bonded in a distorted trigonal planar geometry to one Ba and three Ge atoms. In the sixth O site, O is bonded in a distorted water-like geometry to two equivalent Ba and two Ge atoms. In the seventh O site, O is bonded in a distorted single-bond geometry to two equivalent Ba and one Ge atom. In the eighth O site, O is bonded in a distorted single-bond geometry to two equivalent Ba and one Ge atom.