Materials Data on BaGe(PO4)2 by Materials Project
BaGe(PO4)2 crystallizes in the monoclinic C2/m space group. The structure is three-dimensional. Ba2+ is bonded in a 10-coordinate geometry to ten O2- atoms. There are a spread of Ba–O bond distances ranging from 2.83–3.08 Å. Ge4+ is bonded to six O2- atoms to form GeO6 octahedra that share corners with six equivalent PO4 tetrahedra. There is two shorter (1.86 Å) and four longer (1.91 Å) Ge–O bond length. P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share corners with three equivalent GeO6 octahedra. The corner-sharing octahedra tilt angles range from 35–45°. There is two shorter (1.53 Å) and two longer (1.57 Å) P–O bond length. There are three inequivalent O2- sites. In the first O2- site, O2- is bonded in a bent 150 degrees geometry to one Ge4+ and one P5+ atom. In the second O2- site, O2- is bonded in a distorted single-bond geometry to three equivalent Ba2+ and one P5+ atom. In the third O2- site, O2- is bonded in a 2-coordinate geometry to one Ba2+, one Ge4+, and one P5+ atom.