Materials Data on BaGa2(SiO4)2 by Materials Project
BaGa2Si2O8 crystallizes in the monoclinic C2/c space group. The structure is three-dimensional. Ba2+ is bonded in a 9-coordinate geometry to nine O2- atoms. There are a spread of Ba–O bond distances ranging from 2.67–3.29 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 four SiO4 tetrahedra. There are a spread of Ga–O bond distances ranging from 1.82–1.87 Å. In the second Ga3+ site, Ga3+ is bonded to four O2- atoms to form GaO4 tetrahedra that share corners with four SiO4 tetrahedra. There are a spread of Ga–O bond distances ranging from 1.83–1.86 Å. There are two inequivalent Si4+ sites. In the first Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share corners with four GaO4 tetrahedra. There is two shorter (1.64 Å) and two longer (1.65 Å) Si–O bond length. In the second Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share corners with four GaO4 tetrahedra. There are a spread of Si–O bond distances ranging from 1.63–1.66 Å. There are eight inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted trigonal planar geometry to one Ba2+, one Ga3+, and one Si4+ atom. In the second O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one Ba2+, one Ga3+, and one Si4+ atom. In the third O2- site, O2- is bonded in a 2-coordinate geometry to one Ba2+, one Ga3+, and one Si4+ atom. In the fourth O2- site, O2- is bonded in a 2-coordinate geometry to one Ba2+, one Ga3+, and one Si4+ atom. In the fifth O2- site, O2- is bonded in a 2-coordinate geometry to two equivalent Ba2+, one Ga3+, and one Si4+ atom. In the sixth O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one Ba2+, one Ga3+, and one Si4+ atom. In the seventh O2- site, O2- is bonded in a bent 120 degrees geometry to one Ba2+, one Ga3+, and one Si4+ atom. In the eighth O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one Ba2+, one Ga3+, and one Si4+ atom.