Materials Data on Ba2Ti(GeO4)2 by Materials Project
Ba2TiGe2O8 crystallizes in the tetragonal P4bm space group. The structure is three-dimensional. Ba2+ is bonded in a 8-coordinate geometry to eight O2- atoms. There are a spread of Ba–O bond distances ranging from 2.75–3.08 Å. Ti4+ is bonded in a 5-coordinate geometry to five O2- atoms. There is one shorter (1.70 Å) and four longer (1.99 Å) Ti–O bond length. Ge4+ is bonded to four O2- atoms to form corner-sharing GeO4 tetrahedra. There are a spread of Ge–O bond distances ranging from 1.73–1.82 Å. There are four inequivalent O2- sites. In the first O2- site, O2- is bonded in a single-bond geometry to one Ti4+ atom. In the second O2- site, O2- is bonded to three equivalent Ba2+ and one Ge4+ atom to form a mixture of distorted edge and corner-sharing OBa3Ge tetrahedra. In the third O2- site, O2- is bonded in a 2-coordinate geometry to two equivalent Ba2+, one Ti4+, and one Ge4+ atom. In the fourth O2- site, O2- is bonded in a 4-coordinate geometry to two equivalent Ba2+ and two equivalent Ge4+ atoms.