Materials Data on BaMgSiO4 by Materials Project

Abstract

BaMgSiO4 crystallizes in the hexagonal P6_3 space group. The structure is three-dimensional. there are three inequivalent Ba2+ sites. In the first Ba2+ site, Ba2+ is bonded in a distorted q6 geometry to nine O2- atoms. There are a spread of Ba–O bond distances ranging from 2.76–3.16 Å. In the second Ba2+ site, Ba2+ is bonded in a distorted q6 geometry to nine O2- atoms. There are a spread of Ba–O bond distances ranging from 2.81–3.04 Å. In the third Ba2+ site, Ba2+ is bonded in a 6-coordinate geometry to six O2- atoms. There are three shorter (2.75 Å) and three longer (2.83 Å) Ba–O bond lengths. Mg2+ is bonded to four O2- atoms to form MgO4 tetrahedra that share corners with four equivalent SiO4 tetrahedra. There is one shorter (1.94 Å) and three longer (1.96 Å) Mg–O bond length. Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share corners with four equivalent MgO4 tetrahedra. All Si–O bond lengths are 1.65 Å. There are four inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted bent 150 degrees geometry to two Ba2+, one Mg2+, and one Si4+ atom. In the second O2- site, O2- is bonded in a 2-coordinate geometry to two Ba2+, one Mg2+, and one Si4+ atom. In the third O2- site, O2- is bonded in a distorted bent 120 degrees geometry to two equivalent Ba2+, one Mg2+, and one Si4+ atom. In the fourth O2- site, O2- is bonded in a 2-coordinate geometry to two Ba2+, one Mg2+, and one Si4+ atom.