Materials Data on MgSiO3 by Materials Project

Abstract

MgSiO3 crystallizes in the orthorhombic Pna2_1 space group. The structure is three-dimensional. there are two inequivalent Mg2+ sites. In the first Mg2+ site, Mg2+ is bonded to four O2- atoms to form MgO4 tetrahedra that share corners with four SiO4 tetrahedra, corners with two equivalent MgO5 trigonal bipyramids, and an edgeedge with one MgO5 trigonal bipyramid. There are a spread of Mg–O bond distances ranging from 1.95–2.01 Å. In the second Mg2+ site, Mg2+ is bonded to five O2- atoms to form distorted MgO5 trigonal bipyramids that share corners with two equivalent MgO4 tetrahedra, corners with two equivalent SiO4 tetrahedra, an edgeedge with one MgO4 tetrahedra, and edges with two SiO4 tetrahedra. There are a spread of Mg–O bond distances ranging from 1.99–2.19 Å. There are two inequivalent Si4+ sites. In the first Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share corners with two equivalent MgO4 tetrahedra, corners with two equivalent SiO4 tetrahedra, corners with two equivalent MgO5 trigonal bipyramids, and an edgeedge with one MgO5 trigonal bipyramid. There are a spread of Si–O bond distances ranging from 1.60–1.71 Å. In the second Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share corners with two equivalent MgO4 tetrahedra, corners with two equivalent SiO4 tetrahedra, and an edgeedge with one MgO5 trigonal bipyramid. There are a spread of Si–O bond distances ranging from 1.64–1.66 Å. There are six inequivalent O2- sites. In the first O2- site, O2- is bonded in a trigonal planar geometry to one Mg2+ and two equivalent Si4+ atoms. In the second O2- site, O2- is bonded in a distorted trigonal planar geometry to two Mg2+ and one Si4+ atom. In the third O2- site, O2- is bonded in a distorted T-shaped geometry to two Mg2+ and one Si4+ atom. In the fourth O2- site, O2- is bonded in a distorted bent 120 degrees geometry to two equivalent Si4+ atoms. In the fifth O2- site, O2- is bonded in a T-shaped geometry to two Mg2+ and one Si4+ atom. In the sixth O2- site, O2- is bonded in a T-shaped geometry to two Mg2+ and one Si4+ atom.