Materials Data on MgSi(HO2)2 by Materials Project

MgSiO2(OH)2 is Pb(Zr_(1-x)Ti_x)O3-derived structured and crystallizes in the monoclinic Pm space group. The structure is three-dimensional. Mg2+ is bonded to six O2- atoms to form distorted 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 50–57°. There are a spread of Mg–O bond distances ranging from 2.00–2.20 Å. 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 50–57°. There are a spread of Si–O bond distances ranging from 1.71–1.94 Å. There are two inequivalent H1+ sites. In the first H1+ site, H1+ is bonded in a linear geometry to two O2- atoms. There is one shorter (1.05 Å) and one longer (1.50 Å) H–O bond length. In the second H1+ site, H1+ is bonded in a linear geometry to two O2- atoms. There is one shorter (1.06 Å) and one longer (1.44 Å) H–O bond length. There are four inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to two equivalent Mg2+, one Si4+, and one H1+ atom. In the second O2- site, O2- is bonded in a distorted single-bond geometry to one Mg2+, two equivalent Si4+, and one H1+ atom. In the third O2- site, O2- is bonded in a distorted single-bond geometry to two equivalent Mg2+, one Si4+, and one H1+ atom. In the fourth O2- site, O2- is bonded in a 4-coordinate geometry to one Mg2+, two equivalent Si4+, and one H1+ atom.