DOI: 10.17188/1350860
title: Materials Data on MgSiO3 by Materials Project

description: MgSiO3 crystallizes in the monoclinic P2/c space group. The structure is three-dimensional. there are six inequivalent Mg2+ sites. In the first Mg2+ site, Mg2+ is bonded to six O2- atoms to form MgO6 octahedra that share corners with six SiO4 tetrahedra and edges with five MgO6 octahedra. There are a spread of Mg–O bond distances ranging from 2.05–2.23 Å. In the second Mg2+ site, Mg2+ is bonded to six O2- atoms to form distorted MgO6 octahedra that share corners with four 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 2.03–2.32 Å. In the third Mg2+ site, Mg2+ is bonded to six O2- atoms to form MgO6 octahedra that share corners with six SiO4 tetrahedra and edges with two equivalent MgO6 octahedra. There are a spread of Mg–O bond distances ranging from 2.07–2.24 Å. In the fourth Mg2+ site, Mg2+ is bonded in a 5-coordinate geometry to five O2- atoms. There are a spread of Mg–O bond distances ranging from 2.00–2.58 Å. In the fifth Mg2+ site, Mg2+ is bonded to six O2- atoms to form MgO6 octahedra that share corners with six SiO4 tetrahedra and edges with five MgO6 octahedra. There are four shorter (2.08 Å) and two longer (2.22 Å) Mg–O bond lengths. In the sixth Mg2+ site, Mg2+ is bonded to six O2- atoms to form distorted MgO6 octahedra that share corners with eight SiO4 tetrahedra and edges with three equivalent MgO6 octahedra. There are a spread of Mg–O bond distances ranging from 2.02–2.60 Å. There are four inequivalent Si4+ sites. In the first Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share corners with four MgO6 octahedra, corners with two equivalent SiO4 tetrahedra, and an edgeedge with one MgO6 octahedra. The corner-sharing octahedra tilt angles range from 22–61°. There are a spread of Si–O bond distances ranging from 1.60–1.68 Å. In the second Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share corners with four MgO6 octahedra and corners with two equivalent SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 44–61°. There are a spread of Si–O bond distances ranging from 1.62–1.67 Å. In the third Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share corners with six MgO6 octahedra and corners with two equivalent SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 46–72°. There are a spread of Si–O bond distances ranging from 1.61–1.69 Å. In the fourth Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share corners with four MgO6 octahedra and corners with two equivalent SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 46–60°. There are a spread of Si–O bond distances ranging from 1.61–1.69 Å. There are twelve 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 distorted T-shaped geometry to two Mg2+ and one Si4+ atom. In the third O2- site, O2- is bonded in a 3-coordinate geometry to one Mg2+ and two equivalent Si4+ atoms. In the fourth 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 fifth O2- site, O2- is bonded in a distorted trigonal planar geometry to two Mg2+ and one Si4+ atom. In the sixth O2- site, O2- is bonded in a distorted bent 120 degrees geometry to two equivalent Si4+ atoms. In the seventh O2- site, O2- is bonded to three Mg2+ and one Si4+ atom to form distorted corner-sharing OMg3Si trigonal pyramids. In the eighth O2- site, O2- is bonded in a distorted trigonal planar geometry to two Mg2+ and one Si4+ atom. In the ninth O2- site, O2- is bonded in a 2-coordinate geometry to one Mg2+ and two equivalent Si4+ atoms. In the tenth O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to three Mg2+ and one Si4+ atom. In the eleventh O2- site, O2- is bonded in a distorted trigonal planar geometry to two Mg2+ and one Si4+ atom. In the twelfth O2- site, O2- is bonded in a 3-coordinate geometry to one Mg2+ and two equivalent Si4+ atoms.