Materials Data on Ba2GeO4 by Materials Project

Abstract

Ba2GeO4 crystallizes in the monoclinic P2_1/c space group. The structure is three-dimensional. there are four inequivalent Ba2+ sites. In the first Ba2+ site, Ba2+ is bonded in a 4-coordinate geometry to four O2- atoms. There are a spread of Ba–O bond distances ranging from 2.54–2.80 Å. In the second Ba2+ site, Ba2+ is bonded to six O2- atoms to form distorted BaO6 octahedra that share corners with four GeO4 tetrahedra, an edgeedge with one BaO6 octahedra, and an edgeedge with one GeO4 tetrahedra. There are a spread of Ba–O bond distances ranging from 2.57–3.14 Å. In the third Ba2+ site, Ba2+ is bonded in a 7-coordinate geometry to seven O2- atoms. There are a spread of Ba–O bond distances ranging from 2.61–3.21 Å. In the fourth Ba2+ site, Ba2+ is bonded in a 6-coordinate geometry to six O2- atoms. There are a spread of Ba–O bond distances ranging from 2.65–3.21 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 two equivalent BaO6 octahedra and an edgeedge with one BaO6 octahedra. The corner-sharing octahedra tilt angles range from 8–9°. There is one shorter (1.78 Å) and three longer (1.79 Å) Ge–O bond length. In the second Ge4+ site, Ge4+ is bonded to four O2- atoms to form GeO4 tetrahedra that share corners with two equivalent BaO6 octahedra. The corner-sharing octahedra tilt angles range from 39–63°. There are a spread of Ge–O bond distances ranging from 1.77–1.80 Å. There are eight inequivalent O2- sites. In the first O2- site, O2- is bonded to three Ba2+ and one Ge4+ atom to form distorted corner-sharing OBa3Ge tetrahedra. In the second O2- site, O2- is bonded in a 4-coordinate geometry to three Ba2+ and one Ge4+ atom. In the third O2- site, O2- is bonded in a 4-coordinate geometry to three Ba2+ and one Ge4+ atom. In the fourth O2- site, O2- is bonded in a distorted trigonal planar geometry to two Ba2+ and one Ge4+ atom. In the fifth O2- site, O2- is bonded in a 3-coordinate geometry to three Ba2+ and one Ge4+ atom. In the sixth O2- site, O2- is bonded in a 5-coordinate geometry to four Ba2+ and one Ge4+ atom. In the seventh O2- site, O2- is bonded to three Ba2+ and one Ge4+ atom to form corner-sharing OBa3Ge tetrahedra. In the eighth O2- site, O2- is bonded in a 1-coordinate geometry to two Ba2+ and one Ge4+ atom.