Materials Data on BeAlSiO5 by Materials Project

BeAlSiO5 crystallizes in the monoclinic P2_1/c space group. The structure is three-dimensional. Be is bonded to four O atoms to form BeO4 tetrahedra that share corners with two equivalent AlO6 octahedra, corners with two equivalent BeO4 tetrahedra, and corners with three equivalent SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 47–59°. There is one shorter (1.61 Å) and three longer (1.66 Å) Be–O bond length. Al is bonded to six O atoms to form AlO6 octahedra that share corners with two equivalent BeO4 tetrahedra, corners with five equivalent SiO4 tetrahedra, and edges with two equivalent AlO6 octahedra. There are a spread of Al–O bond distances ranging from 1.86–2.01 Å. Si is bonded to four O atoms to form SiO4 tetrahedra that share corners with five equivalent AlO6 octahedra and corners with three equivalent BeO4 tetrahedra. The corner-sharing octahedra tilt angles range from 47–57°. There are a spread of Si–O bond distances ranging from 1.64–1.66 Å. There are five inequivalent O sites. In the first O site, O is bonded in a distorted trigonal planar geometry to two equivalent Al and one Si atom. In the second O site, O is bonded in a trigonal planar geometry to one Be, one Al, and one Si atom. In the third O site, O is bonded in a trigonal planar geometry to two equivalent Be and one Si atom. In the fourth O site, O is bonded in a distorted trigonal planar geometry to two equivalent Al and one Si atom. In the fifth O site, O is bonded in a distorted bent 120 degrees geometry to one Be and one Al atom.