Materials Data on Mg14Si5O24 by Materials Project

Abstract

Mg14Si5O24 crystallizes in the orthorhombic Pbam 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 five MgO6 octahedra, a cornercorner with one SiO4 tetrahedra, an edgeedge with one SiO6 octahedra, edges with six MgO6 octahedra, and an edgeedge with one SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 3–62°. There are a spread of Mg–O bond distances ranging from 2.07–2.16 Å. In the second Mg2+ site, Mg2+ is bonded to six O2- atoms to form MgO6 octahedra that share corners with six MgO6 octahedra, corners with four SiO4 tetrahedra, an edgeedge with one SiO6 octahedra, and edges with four MgO6 octahedra. The corner-sharing octahedra tilt angles range from 17–62°. There are a spread of Mg–O bond distances ranging from 2.04–2.22 Å. In the third Mg2+ site, Mg2+ is bonded to six O2- atoms to form MgO6 octahedra that share corners with three equivalent MgO6 octahedra, corners with three SiO4 tetrahedra, an edgeedge with one SiO6 octahedra, and edges with seven MgO6 octahedra. The corner-sharing octahedra tilt angles range from 3–14°. There are a spread of Mg–O bond distances ranging from 2.06–2.13 Å. In the fourth Mg2+ site, Mg2+ is bonded to six O2- atoms to form MgO6 octahedra that share corners with six MgO6 octahedra, edges with two equivalent SiO6 octahedra, and edges with eight MgO6 octahedra. The corner-sharing octahedra tilt angles range from 1–17°. All Mg–O bond lengths are 2.14 Å. In the fifth Mg2+ site, Mg2+ is bonded to six O2- atoms to form MgO6 octahedra that share corners with five MgO6 octahedra, corners with three SiO4 tetrahedra, edges with five MgO6 octahedra, and an edgeedge with one SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 1–58°. There are a spread of Mg–O bond distances ranging from 2.00–2.25 Å. In the sixth Mg2+ site, Mg2+ is bonded to six O2- atoms to form MgO6 octahedra that share corners with six SiO4 tetrahedra and edges with six MgO6 octahedra. There are two shorter (2.03 Å) and four longer (2.17 Å) Mg–O bond lengths. There are three inequivalent Si4+ sites. In the first Si4+ site, 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 51–58°. There are a spread of Si–O bond distances ranging from 1.63–1.66 Å. In the second Si4+ site, Si4+ is bonded to six O2- atoms to form SiO6 octahedra that share edges with twelve MgO6 octahedra. There is four shorter (1.82 Å) and two longer (1.84 Å) Si–O bond length. In the third Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share corners with twelve MgO6 octahedra. The corner-sharing octahedra tilt angles range from 52–57°. There is one shorter (1.67 Å) and three longer (1.68 Å) Si–O bond length. There are nine inequivalent O2- sites. In the first O2- site, O2- is bonded in a 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 to six Mg2+ atoms to form OMg6 octahedra that share a cornercorner with one OMg6 octahedra and edges with six OMg4Si square pyramids. The corner-sharing octahedral tilt angles are 0°. In the fourth O2- site, O2- is bonded in a rectangular see-saw-like geometry to three Mg2+ and one Si4+ atom. In the fifth O2- site, O2- is bonded in a rectangular see-saw-like geometry to three Mg2+ and one Si4+ atom. In the sixth O2- site, O2- is bonded to four Mg2+ and one Si4+ atom to form OMg4Si square pyramids that share corners with three equivalent OMg4Si square pyramids, edges with two equivalent OMg6 octahedra, and edges with four OMg4Si square pyramids. In the seventh O2- site, O2- is bonded to four Mg2+ and one Si4+ atom to form OMg4Si square pyramids that share a cornercorner with one OMg4Si square pyramid, edges with two equivalent OMg6 octahedra, and edges with four equivalent OMg4Si square pyramids. In the eighth O2- site, O2- is bonded in a rectangular see-saw-like geometry to three Mg2+ and one Si4+ atom. In the ninth O2- site, O2- is bonded in a rectangular see-saw-like geometry to three Mg2+ and one Si4+ atom.