Materials Data on MgAlSi4O15 by Materials Project

Abstract

MgAlSi4O13O2 crystallizes in the monoclinic C2/m space group. The structure is three-dimensional and consists of eight water molecules and one MgAlSi4O13 framework. In the MgAlSi4O13 framework, Mg is bonded to six O atoms to form distorted MgO6 octahedra that share corners with four SiO4 tetrahedra and an edgeedge with one MgO6 octahedra. There are a spread of Mg–O bond distances ranging from 1.98–2.08 Å. Al is bonded in a 6-coordinate geometry to six O atoms. There are a spread of Al–O bond distances ranging from 1.80–2.18 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 and corners with three SiO4 tetrahedra. The corner-sharing octahedral tilt angles are 57°. 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 and corners with three SiO4 tetrahedra. The corner-sharing octahedral tilt angles are 59°. There are a spread of Si–O bond distances ranging from 1.62–1.65 Å. There are eight inequivalent O sites. In the first O site, O is bonded in a linear geometry to two equivalent Si atoms. In the second O site, O is bonded in a 3-coordinate geometry to two equivalent Mg and one O atom. The O–O bond length is 1.38 Å. 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 120 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 2-coordinate geometry to one Al and one O atom. The O–O bond length is 1.29 Å. 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.