Materials Data on Al2SiO5 by Materials Project

Abstract

Al2SiO5 crystallizes in the triclinic P-1 space group. The structure is three-dimensional. there are four inequivalent Al3+ sites. In the first Al3+ site, Al3+ is bonded to six O2- atoms to form AlO6 octahedra that share corners with five SiO4 tetrahedra and edges with four AlO6 octahedra. There are a spread of Al–O bond distances ranging from 1.83–2.02 Å. In the second Al3+ site, Al3+ is bonded to six O2- atoms to form AlO6 octahedra that share corners with two equivalent AlO6 octahedra, corners with three SiO4 tetrahedra, and edges with five AlO6 octahedra. The corner-sharing octahedra tilt angles range from 16–19°. There are a spread of Al–O bond distances ranging from 1.88–2.01 Å. In the third Al3+ site, Al3+ is bonded to six O2- atoms to form AlO6 octahedra that share corners with two equivalent AlO6 octahedra, corners with four SiO4 tetrahedra, and edges with four AlO6 octahedra. The corner-sharing octahedra tilt angles range from 16–19°. There are a spread of Al–O bond distances ranging from 1.90–1.96 Å. In the fourth Al3+ site, Al3+ is bonded to six O2- atoms to form AlO6 octahedra that share corners with four SiO4 tetrahedra and edges with five AlO6 octahedra. There are a spread of Al–O bond distances ranging from 1.87–2.01 Å. There are two inequivalent Si4+ sites. In the first Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share corners with eight AlO6 octahedra. The corner-sharing octahedra tilt angles range from 49–54°. There are a spread of Si–O bond distances ranging from 1.64–1.66 Å. In the second Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share corners with eight AlO6 octahedra. The corner-sharing octahedra tilt angles range from 48–56°. There are a spread of Si–O bond distances ranging from 1.64–1.66 Å. There are ten inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted trigonal planar geometry to two Al3+ and one Si4+ atom. In the second O2- site, O2- is bonded in a distorted trigonal planar geometry to two Al3+ and one Si4+ atom. In the third O2- site, O2- is bonded in a distorted trigonal planar geometry to two Al3+ and one Si4+ atom. In the fourth O2- site, O2- is bonded in a distorted trigonal planar geometry to two Al3+ and one Si4+ atom. In the fifth O2- site, O2- is bonded to four Al3+ atoms to form distorted edge-sharing OAl4 trigonal pyramids. In the sixth O2- site, O2- is bonded in a distorted trigonal planar geometry to two Al3+ and one Si4+ atom. In the seventh O2- site, O2- is bonded in a 3-coordinate geometry to two equivalent Al3+ and one Si4+ atom. In the eighth O2- site, O2- is bonded in a see-saw-like geometry to four Al3+ atoms. In the ninth O2- site, O2- is bonded in a distorted trigonal planar geometry to two Al3+ and one Si4+ atom. In the tenth O2- site, O2- is bonded in a distorted trigonal planar geometry to two Al3+ and one Si4+ atom.