Materials Data on Mg2SiO4 by Materials Project

Mg2SiO4 is Ilmenite-like structured and crystallizes in the monoclinic C2/m space group. The structure is three-dimensional. there are three inequivalent Mg2+ sites. In the first Mg2+ site, Mg2+ is bonded to six O2- atoms to form MgO6 octahedra that share corners with two equivalent SiO4 tetrahedra, edges with six MgO6 octahedra, and edges with two equivalent SiO4 tetrahedra. There are four shorter (2.02 Å) and two longer (2.17 Å) Mg–O bond lengths. In the second Mg2+ site, Mg2+ is bonded to six O2- atoms to form MgO6 octahedra that share corners with six equivalent SiO4 tetrahedra and edges with six MgO6 octahedra. There are two shorter (2.33 Å) and four longer (2.34 Å) Mg–O bond lengths. In the third Mg2+ site, Mg2+ is bonded to six O2- atoms to form MgO6 octahedra that share corners with two equivalent SiO4 tetrahedra, edges with six MgO6 octahedra, and edges with two equivalent SiO4 tetrahedra. There are four shorter (2.02 Å) and two longer (2.17 Å) Mg–O bond lengths. Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share corners with six MgO6 octahedra and edges with three MgO6 octahedra. The corner-sharing octahedra tilt angles range from 3–55°. There is one shorter (1.61 Å) and three longer (1.69 Å) Si–O bond length. 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 rectangular see-saw-like geometry to three Mg2+ and one Si4+ atom. In the third O2- site, O2- is bonded in a rectangular see-saw-like geometry to three Mg2+ and one Si4+ atom.