Materials Data on Ba3NbGa3(SiO7)2 by Materials Project

Abstract

Ba3NbGa3(SiO7)2 is Esseneite-derived structured and crystallizes in the trigonal P321 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 2.72–3.06 Å. Nb5+ is bonded to six equivalent O2- atoms to form NbO6 octahedra that share corners with six equivalent GaO4 tetrahedra. All Nb–O bond lengths are 2.02 Å. Ga3+ is bonded to four O2- atoms to form GaO4 tetrahedra that share corners with two equivalent NbO6 octahedra and corners with two equivalent SiO4 tetrahedra. The corner-sharing octahedral tilt angles are 53°. There is two shorter (1.84 Å) and two longer (1.90 Å) Ga–O bond length. Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share corners with three equivalent GaO4 tetrahedra. There is one shorter (1.61 Å) and three longer (1.67 Å) Si–O bond length. There are three inequivalent O2- sites. In the first O2- site, O2- is bonded in a 3-coordinate geometry to one Ba2+, one Nb5+, and one Ga3+ atom. In the second O2- site, O2- is bonded in a 2-coordinate geometry to two equivalent Ba2+, one Ga3+, and one Si4+ atom. In the third O2- site, O2- is bonded in a distorted single-bond geometry to three equivalent Ba2+ and one Si4+ atom.