Materials Data on MgSi(HO2)2 by Materials Project

Abstract

MgSiO2(OH)2 crystallizes in the monoclinic P2/m space group. The structure is three-dimensional. Mg2+ is bonded to six O2- atoms to form MgO6 octahedra that share corners with eight equivalent SiO6 octahedra and edges with two equivalent MgO6 octahedra. The corner-sharing octahedra tilt angles range from 52–55°. There are four shorter (2.05 Å) and two longer (2.18 Å) Mg–O bond lengths. Si4+ is bonded to six O2- atoms to form SiO6 octahedra that share corners with eight equivalent MgO6 octahedra and edges with two equivalent SiO6 octahedra. The corner-sharing octahedra tilt angles range from 52–55°. There is two shorter (1.76 Å) and four longer (1.88 Å) Si–O bond length. There are two inequivalent H1+ sites. In the first H1+ site, H1+ is bonded in a linear geometry to two equivalent O2- atoms. Both H–O bond lengths are 1.22 Å. In the second H1+ site, H1+ is bonded in a linear geometry to two equivalent O2- atoms. Both H–O bond lengths are 1.21 Å. There are two inequivalent O2- sites. In the first O2- site, O2- is bonded in a 4-coordinate geometry to two equivalent Mg2+, one Si4+, and one H1+ atom. In the second O2- site, O2- is bonded in a 1-coordinate geometry to one Mg2+, two equivalent Si4+, and one H1+ atom.