Materials Data on MgSiO3 by Materials Project

Abstract

MgSiO3 is Esseneite-derived structured and 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 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 2.03–2.23 Å. In the second Mg2+ site, Mg2+ is bonded to six O2- atoms to form distorted MgO6 octahedra that share corners with four equivalent SiO4 tetrahedra, edges with three equivalent MgO6 octahedra, and edges with two equivalent SiO4 tetrahedra. There are a spread of Mg–O bond distances ranging from 2.06–2.37 Å. Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share corners with five MgO6 octahedra, corners with two equivalent SiO4 tetrahedra, and an edgeedge with one MgO6 octahedra. The corner-sharing octahedra tilt angles range from 30–60°. There are a spread of Si–O bond distances ranging from 1.61–1.68 Å. There are three inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to three Mg2+ and one Si4+ atom. In the second O2- site, O2- is bonded in a 2-coordinate geometry to one Mg2+ and two equivalent Si4+ atoms. In the third O2- site, O2- is bonded in a distorted T-shaped geometry to two Mg2+ and one Si4+ atom.