Materials Data on Mg7(SiO4)4 by Materials Project
Mg7(SiO4)4 is beta indium sulfide-derived structured and crystallizes in the monoclinic C2 space group. The structure is three-dimensional. there are five inequivalent Mg sites. In the first Mg site, Mg is bonded to six O atoms to form MgO6 octahedra that share corners with six SiO4 tetrahedra and edges with five MgO6 octahedra. There are a spread of Mg–O bond distances ranging from 2.03–2.28 Å. In the second Mg site, Mg is bonded to six O atoms to form MgO6 octahedra that share corners with six SiO4 tetrahedra and edges with five MgO6 octahedra. There are a spread of Mg–O bond distances ranging from 2.05–2.16 Å. In the third Mg site, Mg is bonded to six O atoms to form MgO6 octahedra that share corners with four SiO4 tetrahedra and edges with seven MgO6 octahedra. There are a spread of Mg–O bond distances ranging from 2.05–2.14 Å. In the fourth Mg site, Mg is bonded to six O atoms to form MgO6 octahedra that share corners with two equivalent MgO6 octahedra, corners with four SiO4 tetrahedra, and edges with five MgO6 octahedra. The corner-sharing octahedral tilt angles are 16°. There are a spread of Mg–O bond distances ranging from 2.07–2.18 Å. In the fifth Mg site, Mg is bonded to six O atoms to form MgO6 octahedra that share corners with two equivalent MgO6 octahedra, corners with four SiO4 tetrahedra, and edges with six MgO6 octahedra. The corner-sharing octahedral tilt angles are 16°. There are a spread of Mg–O bond distances ranging from 2.05–2.13 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 corners with nine MgO6 octahedra and a cornercorner with one SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 47–62°. There are a spread of Si–O bond distances ranging from 1.63–1.73 Å. In the second Si site, Si is bonded to four O atoms to form SiO4 tetrahedra that share corners with nine MgO6 octahedra and a cornercorner with one SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 42–60°. There are a spread of Si–O bond distances ranging from 1.64–1.71 Å. There are eight inequivalent O sites. In the first O site, O is bonded in a rectangular see-saw-like geometry to three Mg and one Si atom. In the second O site, O is bonded in a rectangular see-saw-like geometry to three Mg and one Si atom. In the third O site, O is bonded in a 3-coordinate geometry to two Mg and one Si atom. In the fourth O site, O is bonded in a rectangular see-saw-like geometry to three Mg and one Si atom. In the fifth O site, O is bonded in a see-saw-like geometry to four Mg atoms. In the sixth O site, O is bonded in a trigonal planar geometry to one Mg and two Si atoms. In the seventh O site, O is bonded in a distorted trigonal planar geometry to two Mg and one Si atom. In the eighth O site, O is bonded in a distorted rectangular see-saw-like geometry to three Mg and one Si atom.