Materials Data on CaTiGeO5 by Materials Project
CaTiGeO5 crystallizes in the monoclinic P2_1/c space group. The structure is three-dimensional. Ca2+ is bonded in a 7-coordinate geometry to seven O2- atoms. There are a spread of Ca–O bond distances ranging from 2.32–2.64 Å. Ti4+ is bonded to six O2- atoms to form TiO6 octahedra that share corners with two equivalent TiO6 octahedra and corners with four equivalent GeO4 tetrahedra. The corner-sharing octahedral tilt angles are 37°. There are a spread of Ti–O bond distances ranging from 1.80–2.05 Å. Ge4+ is bonded to four O2- atoms to form GeO4 tetrahedra that share corners with four equivalent TiO6 octahedra. The corner-sharing octahedra tilt angles range from 39–57°. There is three shorter (1.77 Å) and one longer (1.78 Å) Ge–O bond length. There are five inequivalent O2- sites. In the first O2- site, O2- is bonded to two equivalent Ca2+, one Ti4+, and one Ge4+ atom to form distorted edge-sharing OCa2TiGe tetrahedra. In the second O2- site, O2- is bonded in a 4-coordinate geometry to two equivalent Ca2+, one Ti4+, and one Ge4+ atom. In the third O2- site, O2- is bonded in a 3-coordinate geometry to one Ca2+, one Ti4+, and one Ge4+ atom. In the fourth O2- site, O2- is bonded in a 3-coordinate geometry to one Ca2+ and two equivalent Ti4+ atoms. In the fifth O2- site, O2- is bonded in a 3-coordinate geometry to one Ca2+, one Ti4+, and one Ge4+ atom.