Materials Data on BaGe2O5 by Materials Project
BaGe2O5 crystallizes in the orthorhombic Cmce space group. The structure is three-dimensional. Ba2+ is bonded to twelve O2- atoms to form BaO12 cuboctahedra that share corners with eight equivalent BaO12 cuboctahedra, corners with four equivalent GeO4 tetrahedra, an edgeedge with one GeO6 octahedra, edges with three equivalent GeO4 tetrahedra, faces with three equivalent BaO12 cuboctahedra, and faces with four equivalent GeO6 octahedra. There are a spread of Ba–O bond distances ranging from 2.82–3.17 Å. There are two inequivalent Ge4+ sites. In the first Ge4+ site, Ge4+ is bonded to four O2- atoms to form GeO4 tetrahedra that share corners with four equivalent BaO12 cuboctahedra, corners with four equivalent GeO6 octahedra, and edges with three equivalent BaO12 cuboctahedra. The corner-sharing octahedra tilt angles range from 55–64°. There are a spread of Ge–O bond distances ranging from 1.75–1.82 Å. In the second Ge4+ site, Ge4+ is bonded to six O2- atoms to form GeO6 octahedra that share corners with two equivalent GeO6 octahedra, corners with four equivalent GeO4 tetrahedra, an edgeedge with one BaO12 cuboctahedra, and faces with four equivalent BaO12 cuboctahedra. The corner-sharing octahedral tilt angles are 48°. There are a spread of Ge–O bond distances ranging from 1.86–2.06 Å. There are four inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted bent 120 degrees geometry to two equivalent Ba2+ and two equivalent Ge4+ atoms. In the second O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one Ba2+ and two Ge4+ atoms. In the third O2- site, O2- is bonded in a distorted bent 120 degrees geometry to three equivalent Ba2+ and two Ge4+ atoms. In the fourth O2- site, O2- is bonded in a distorted bent 120 degrees geometry to three equivalent Ba2+ and two Ge4+ atoms.