Materials Data on Ca2Ga2GeO7 by Materials Project
Ca2Ga2GeO7 crystallizes in the monoclinic P2_1 space group. The structure is three-dimensional. there are two inequivalent Ca2+ sites. In the first Ca2+ site, Ca2+ is bonded in a 7-coordinate geometry to eight O2- atoms. There are a spread of Ca–O bond distances ranging from 2.39–3.08 Å. In the second Ca2+ site, Ca2+ is bonded in a 8-coordinate geometry to eight O2- atoms. There are a spread of Ca–O bond distances ranging from 2.43–3.01 Å. There are two inequivalent Ga3+ sites. In the first Ga3+ site, Ga3+ is bonded to four O2- atoms to form GaO4 tetrahedra that share corners with two equivalent GaO4 tetrahedra and corners with two equivalent GeO4 tetrahedra. There are a spread of Ga–O bond distances ranging from 1.83–1.87 Å. In the second Ga3+ site, Ga3+ is bonded to four O2- atoms to form distorted GaO4 tetrahedra that share a cornercorner with one GeO4 tetrahedra and corners with two equivalent GaO4 tetrahedra. There are a spread of Ga–O bond distances ranging from 1.80–1.89 Å. Ge4+ is bonded to four O2- atoms to form GeO4 tetrahedra that share corners with three GaO4 tetrahedra. There are a spread of Ge–O bond distances ranging from 1.73–1.79 Å. There are seven inequivalent O2- sites. In the first O2- site, O2- is bonded to two Ca2+, one Ga3+, and one Ge4+ atom to form a mixture of distorted edge and corner-sharing OCa2GaGe tetrahedra. In the second O2- site, O2- is bonded to three Ca2+ and one Ga3+ atom to form a mixture of distorted edge and corner-sharing OCa3Ga tetrahedra. In the third O2- site, O2- is bonded in a 4-coordinate geometry to three Ca2+ and one Ge4+ atom. In the fourth O2- site, O2- is bonded in a 3-coordinate geometry to two equivalent Ca2+, one Ga3+, and one Ge4+ atom. In the fifth O2- site, O2- is bonded in a 4-coordinate geometry to two equivalent Ca2+ and two Ga3+ atoms. In the sixth O2- site, O2- is bonded in a 4-coordinate geometry to two Ca2+ and two Ga3+ atoms. In the seventh O2- site, O2- is bonded in a 2-coordinate geometry to two Ca2+, one Ga3+, and one Ge4+ atom.