DOI: 10.17188/1301255
title: Materials Data on Al8SiO14 by Materials Project

description: Al8SiO14 crystallizes in the orthorhombic Pnma space group. The structure is three-dimensional. there are seven inequivalent Al3+ sites. In the first Al3+ site, Al3+ is bonded to six O2- atoms to form AlO6 octahedra that share corners with two equivalent SiO4 tetrahedra, corners with six AlO4 tetrahedra, and edges with two equivalent AlO6 octahedra. There are a spread of Al–O bond distances ranging from 1.90–2.00 Å. In the second Al3+ site, Al3+ is bonded to four O2- atoms to form AlO4 tetrahedra that share corners with four AlO6 octahedra and corners with four AlO4 tetrahedra. The corner-sharing octahedra tilt angles range from 59–64°. There is three shorter (1.76 Å) and one longer (1.87 Å) Al–O bond length. In the third Al3+ site, Al3+ is bonded to four O2- atoms to form AlO4 tetrahedra that share corners with four AlO6 octahedra, a cornercorner with one SiO4 tetrahedra, and corners with three AlO4 tetrahedra. The corner-sharing octahedra tilt angles range from 56–64°. There are a spread of Al–O bond distances ranging from 1.73–1.96 Å. In the fourth Al3+ site, Al3+ is bonded to four O2- atoms to form AlO4 tetrahedra that share corners with four AlO6 octahedra, corners with two AlO4 tetrahedra, and corners with two equivalent SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 54–63°. There are a spread of Al–O bond distances ranging from 1.76–1.81 Å. In the fifth Al3+ site, Al3+ is bonded to six O2- atoms to form AlO6 octahedra that share a cornercorner with one SiO4 tetrahedra, corners with seven AlO4 tetrahedra, and edges with two equivalent AlO6 octahedra. There are a spread of Al–O bond distances ranging from 1.89–2.09 Å. In the sixth Al3+ site, Al3+ is bonded to four O2- atoms to form AlO4 tetrahedra that share corners with four equivalent AlO6 octahedra and corners with four AlO4 tetrahedra. The corner-sharing octahedra tilt angles range from 51–60°. There are a spread of Al–O bond distances ranging from 1.73–1.82 Å. In the seventh Al3+ site, Al3+ is bonded to four O2- atoms to form AlO4 tetrahedra that share corners with four equivalent AlO6 octahedra, a cornercorner with one SiO4 tetrahedra, and corners with three AlO4 tetrahedra. The corner-sharing octahedra tilt angles range from 52–61°. There is three shorter (1.74 Å) and one longer (1.89 Å) Al–O bond length. Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share corners with four AlO6 octahedra and corners with four AlO4 tetrahedra. The corner-sharing octahedra tilt angles range from 52–55°. There are a spread of Si–O bond distances ranging from 1.65–1.69 Å. There are eleven inequivalent O2- sites. In the first O2- site, O2- is bonded in a trigonal planar geometry to three Al3+ atoms. In the second O2- site, O2- is bonded in a trigonal planar geometry to three Al3+ atoms. In the third O2- site, O2- is bonded in a distorted trigonal planar geometry to two equivalent Al3+ and one Si4+ atom. In the fourth O2- site, O2- is bonded in a distorted trigonal planar geometry to three Al3+ atoms. In the fifth O2- site, O2- is bonded in a trigonal planar geometry to three Al3+ atoms. In the sixth O2- site, O2- is bonded in a trigonal planar geometry to two Al3+ and one Si4+ atom. In the seventh O2- site, O2- is bonded in a distorted trigonal non-coplanar geometry to three Al3+ atoms. In the eighth O2- site, O2- is bonded in a distorted trigonal non-coplanar geometry to two Al3+ and one Si4+ atom. In the ninth O2- site, O2- is bonded in a trigonal planar geometry to three Al3+ atoms. In the tenth O2- site, O2- is bonded in a trigonal planar geometry to three Al3+ atoms. In the eleventh O2- site, O2- is bonded in a trigonal planar geometry to three Al3+ atoms.