Materials Data on Ga4SiO8 by Materials Project
Ga4SiO8 crystallizes in the monoclinic C2/m space group. The structure is three-dimensional. there are two inequivalent Ga3+ sites. In the first Ga3+ site, Ga3+ is bonded to six O2- atoms to form GaO6 octahedra that share corners with two equivalent SiO6 octahedra, corners with five equivalent GaO4 tetrahedra, and edges with four equivalent GaO6 octahedra. The corner-sharing octahedral tilt angles are 51°. There are a spread of Ga–O bond distances ranging from 1.93–2.12 Å. In the second Ga3+ site, Ga3+ is bonded to four O2- atoms to form GaO4 tetrahedra that share corners with two equivalent SiO6 octahedra, corners with five equivalent GaO6 octahedra, and corners with two equivalent GaO4 tetrahedra. The corner-sharing octahedra tilt angles range from 55–70°. There are a spread of Ga–O bond distances ranging from 1.83–1.90 Å. Si4+ is bonded to six O2- atoms to form SiO6 octahedra that share corners with four equivalent GaO6 octahedra, corners with four equivalent GaO4 tetrahedra, and edges with two equivalent SiO6 octahedra. The corner-sharing octahedral tilt angles are 51°. There is two shorter (1.73 Å) and four longer (1.90 Å) Si–O bond length. There are four inequivalent O2- sites. In the first O2- site, O2- is bonded in a trigonal planar geometry to three Ga3+ atoms. In the second O2- site, O2- is bonded in a distorted trigonal planar geometry to two equivalent Ga3+ and one Si4+ atom. In the third O2- site, O2- is bonded to four Ga3+ atoms to form a mixture of distorted edge and corner-sharing OGa4 tetrahedra. In the fourth O2- site, O2- is bonded in a trigonal planar geometry to one Ga3+ and two equivalent Si4+ atoms.