DOI: 10.17188/1721992
title: Materials Data on NaAl3(SiO4)3 by Materials Project

description: NaAl3(SiO4)3 crystallizes in the monoclinic Cc space group. The structure is three-dimensional. Na is bonded in a distorted rectangular see-saw-like geometry to four O atoms. There are a spread of Na–O bond distances ranging from 2.39–2.78 Å. There are three inequivalent Al sites. In the first Al site, Al is bonded to six O atoms to form distorted AlO6 octahedra that share a cornercorner with one AlO4 tetrahedra, corners with three SiO4 tetrahedra, and edges with three equivalent AlO6 octahedra. There are a spread of Al–O bond distances ranging from 1.84–1.99 Å. In the second Al site, Al is bonded to six O atoms to form distorted AlO6 octahedra that share a cornercorner with one AlO4 tetrahedra, corners with three SiO4 tetrahedra, and edges with three equivalent AlO6 octahedra. There are a spread of Al–O bond distances ranging from 1.80–2.00 Å. In the third Al site, Al is bonded to four O atoms to form AlO4 tetrahedra that share corners with two AlO6 octahedra and corners with three equivalent SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 52–55°. There are a spread of Al–O bond distances ranging from 1.75–1.78 Å. There are three inequivalent Si sites. In the first Si site, Si is bonded to four O atoms to form SiO4 tetrahedra that share corners with two AlO6 octahedra and corners with three equivalent SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 45–53°. There are a spread of Si–O bond distances ranging from 1.62–1.66 Å. In the second Si site, Si is bonded to four O atoms to form SiO4 tetrahedra that share corners with two AlO6 octahedra and corners with three equivalent AlO4 tetrahedra. The corner-sharing octahedral tilt angles are 52°. There is three shorter (1.64 Å) and one longer (1.67 Å) Si–O bond length. In the third Si site, Si is bonded to four O atoms to form SiO4 tetrahedra that share corners with two AlO6 octahedra and corners with three equivalent SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 47–53°. There are a spread of Si–O bond distances ranging from 1.63–1.66 Å. There are twelve inequivalent O sites. In the first O site, O is bonded in a trigonal planar geometry to two Al and one Si atom. In the second O site, O is bonded in a distorted trigonal planar geometry to two Al and one Si atom. In the third O site, O is bonded in a 2-coordinate geometry to two Al and one O atom. The O–O bond length is 1.58 Å. In the fourth O site, O is bonded in a 2-coordinate geometry to two Al and one O atom. In the fifth O site, O is bonded in a distorted trigonal planar geometry to one Na, one Al, and one Si atom. In the sixth O site, O is bonded in a 3-coordinate geometry to one Na and two Si atoms. In the seventh O site, O is bonded in a trigonal planar geometry to three Al atoms. In the eighth O site, O is bonded in a distorted trigonal planar geometry to two Al and one Si atom. In the ninth O site, O is bonded in a distorted trigonal planar geometry to one Na, one Al, and one Si atom. In the tenth O site, O is bonded in a bent 150 degrees geometry to two Si atoms. In the eleventh O site, O is bonded in a trigonal planar geometry to one Na, one Al, and one Si atom. In the twelfth O site, O is bonded in a bent 120 degrees geometry to two Si atoms.