Materials Data on MgAlSi4O15 by Materials Project

Abstract

MgAlSi4O13O2 crystallizes in the orthorhombic Pmna space group. The structure is three-dimensional and consists of four molecular oxygen molecules and one MgAlSi4O13 framework. In the MgAlSi4O13 framework, Mg is bonded to six O atoms to form MgO6 octahedra that share corners with four SiO4 tetrahedra, an edgeedge with one MgO6 octahedra, and edges with two equivalent AlO6 octahedra. There are a spread of Mg–O bond distances ranging from 2.02–2.07 Å. Al is bonded to six O atoms to form AlO6 octahedra that share corners with four SiO4 tetrahedra and edges with two equivalent MgO6 octahedra. There are a spread of Al–O bond distances ranging from 1.85–1.96 Å. There are two inequivalent Si sites. In the first Si site, Si is bonded to four O atoms to form SiO4 tetrahedra that share a cornercorner with one MgO6 octahedra, a cornercorner with one AlO6 octahedra, and corners with three SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 47–58°. There are a spread of Si–O bond distances ranging from 1.63–1.65 Å. In the second Si site, Si is bonded to four O atoms to form SiO4 tetrahedra that share a cornercorner with one MgO6 octahedra, a cornercorner with one AlO6 octahedra, and corners with three SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 48–57°. There is one shorter (1.61 Å) and three longer (1.64 Å) Si–O bond length. There are eight inequivalent O sites. In the first O site, O is bonded in a single-bond geometry to one Al atom. In the second O site, O is bonded in a bent 120 degrees geometry to two equivalent Mg atoms. In the third O site, O is bonded in a bent 150 degrees geometry to two equivalent Si atoms. In the fourth O site, O is bonded in a bent 150 degrees geometry to two Si atoms. In the fifth O site, O is bonded in a bent 120 degrees geometry to two Si atoms. In the sixth O site, O is bonded in a linear geometry to two equivalent Si atoms. In the seventh O site, O is bonded in a distorted trigonal planar geometry to one Mg, one Al, and one Si atom. In the eighth O site, O is bonded in a distorted trigonal planar geometry to one Mg, one Al, and one Si atom.