Materials Data on MgSiO3 by Materials Project

Abstract

MgSiO3 crystallizes in the orthorhombic Pbcn space group. The structure is three-dimensional. there are two inequivalent Mg2+ sites. In the first Mg2+ site, Mg2+ is bonded to six O2- atoms to form distorted MgO6 octahedra that share corners with eight equivalent SiO4 tetrahedra and edges with three equivalent MgO6 octahedra. There are a spread of Mg–O bond distances ranging from 1.98–2.50 Å. In the second Mg2+ site, Mg2+ is bonded to six O2- atoms to form MgO6 octahedra that share corners with six equivalent SiO4 tetrahedra and edges with five MgO6 octahedra. There are a spread of Mg–O bond distances ranging from 2.08–2.17 Å. Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share corners with seven MgO6 octahedra and corners with two equivalent SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 43–68°. There are a spread of Si–O bond distances ranging from 1.61–1.69 Å. There are three inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted trigonal planar geometry to one Mg2+ and two equivalent Si4+ atoms. In the second O2- site, O2- is bonded to three Mg2+ and one Si4+ atom to form a mixture of distorted edge and corner-sharing OMg3Si trigonal pyramids. In the third O2- site, O2- is bonded in a distorted trigonal planar geometry to two Mg2+ and one Si4+ atom.