Materials Data on Al2O3 by Materials Project

Abstract

Al2O3 crystallizes in the triclinic P1 space group. The structure is three-dimensional. there are sixteen inequivalent Al3+ sites. In the first Al3+ site, Al3+ is bonded to four O2- atoms to form corner-sharing AlO4 tetrahedra. The corner-sharing octahedra tilt angles range from 52–64°. There are a spread of Al–O bond distances ranging from 1.72–1.86 Å. In the second Al3+ site, Al3+ is bonded to six O2- atoms to form AlO6 octahedra that share corners with three equivalent AlO6 octahedra, corners with two equivalent AlO4 tetrahedra, a cornercorner with one AlO4 trigonal pyramid, and edges with six AlO6 octahedra. The corner-sharing octahedra tilt angles range from 6–12°. There are a spread of Al–O bond distances ranging from 1.88–2.02 Å. In the third Al3+ site, Al3+ is bonded to six O2- atoms to form edge-sharing AlO6 octahedra. There are a spread of Al–O bond distances ranging from 1.79–2.06 Å. In the fourth Al3+ site, Al3+ is bonded to six O2- atoms to form AlO6 octahedra that share corners with two equivalent AlO4 tetrahedra, a cornercorner with one AlO4 trigonal pyramid, and edges with seven AlO6 octahedra. There are a spread of Al–O bond distances ranging from 1.89–1.94 Å. In the fifth Al3+ site, Al3+ is bonded to six O2- atoms to form AlO6 octahedra that share corners with two equivalent AlO4 tetrahedra, a cornercorner with one AlO4 trigonal pyramid, and edges with seven AlO6 octahedra. There are a spread of Al–O bond distances ranging from 1.88–1.99 Å. In the sixth Al3+ site, Al3+ is bonded to four O2- atoms to form corner-sharing AlO4 tetrahedra. The corner-sharing octahedra tilt angles range from 53–61°. There are a spread of Al–O bond distances ranging from 1.79–1.85 Å. In the seventh Al3+ site, Al3+ is bonded to six O2- atoms to form distorted AlO6 octahedra that share corners with three AlO4 tetrahedra and edges with five AlO6 octahedra. There are a spread of Al–O bond distances ranging from 1.80–2.13 Å. In the eighth Al3+ site, Al3+ is bonded to six O2- atoms to form AlO6 octahedra that share corners with six AlO4 tetrahedra and edges with four AlO6 octahedra. There are a spread of Al–O bond distances ranging from 1.89–2.08 Å. In the ninth Al3+ site, Al3+ is bonded in a 6-coordinate geometry to six O2- atoms. There are a spread of Al–O bond distances ranging from 1.79–2.41 Å. In the tenth Al3+ site, Al3+ is bonded to six O2- atoms to form a mixture of edge and corner-sharing AlO6 octahedra. The corner-sharing octahedra tilt angles range from 6–12°. There are a spread of Al–O bond distances ranging from 1.82–2.11 Å. In the eleventh Al3+ site, Al3+ is bonded to six O2- atoms to form distorted AlO6 octahedra that share corners with three AlO4 tetrahedra and edges with five AlO6 octahedra. There are a spread of Al–O bond distances ranging from 1.79–2.32 Å. In the twelfth Al3+ site, Al3+ is bonded to six O2- atoms to form AlO6 octahedra that share corners with four AlO4 tetrahedra, corners with two equivalent AlO4 trigonal pyramids, and edges with four AlO6 octahedra. There are a spread of Al–O bond distances ranging from 1.85–2.05 Å. In the thirteenth Al3+ site, Al3+ is bonded to four O2- atoms to form corner-sharing AlO4 tetrahedra. The corner-sharing octahedra tilt angles range from 53–65°. There are a spread of Al–O bond distances ranging from 1.78–1.85 Å. In the fourteenth Al3+ site, Al3+ is bonded to six O2- atoms to form AlO6 octahedra that share corners with four AlO4 tetrahedra, corners with two equivalent AlO4 trigonal pyramids, and edges with four AlO6 octahedra. There are a spread of Al–O bond distances ranging from 1.83–2.02 Å. In the fifteenth Al3+ site, Al3+ is bonded to four O2- atoms to form corner-sharing AlO4 trigonal pyramids. The corner-sharing octahedra tilt angles range from 40–67°. There are a spread of Al–O bond distances ranging from 1.74–2.03 Å. In the sixteenth Al3+ site, Al3+ is bonded to six O2- atoms to form AlO6 octahedra that share corners with three equivalent AlO4 tetrahedra, corners with three equivalent AlO4 trigonal pyramids, and edges with five AlO6 octahedra. There are a spread of Al–O bond distances ranging from 1.78–2.11 Å. There are twenty-four inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to four Al3+ atoms. In the second O2- site, O2- is bonded in a rectangular see-saw-like geometry to four Al3+ atoms. In the third O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to four Al3+ atoms. In the fourth O2- site, O2- is bonded in a rectangular see-saw-like geometry to four Al3+ atoms. In the fifth O2- site, O2- is bonded to five Al3+ atoms to form edge-sharing OAl5 square pyramids. In the sixth O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to four Al3+ atoms. In the seventh O2- site, O2- is bonded in a distorted trigonal planar geometry to three Al3+ atoms. In the eighth O2- site, O2- is bonded in a rectangular see-saw-like geometry to four Al3+ atoms. In the ninth O2- site, O2- is bonded in a distorted trigonal non-coplanar geometry to three Al3+ atoms. In the tenth O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to four Al3+ atoms. In the eleventh O2- site, O2- is bonded in a rectangular see-saw-like geometry to four Al3+ atoms. In the twelfth O2- site, O2- is bonded to five Al3+ atoms to form distorted edge-sharing OAl5 square pyramids. In the thirteenth O2- site, O2- is bonded in a distorted trigonal planar geometry to three Al3+ atoms. In the fourteenth O2- site, O2- is bonded in a distorted trigonal pyramidal geometry to four Al3+ atoms. In the fifteenth O2- site, O2- is bonded in a distorted trigonal planar geometry to three Al3+ atoms. In the sixteenth O2- site, O2- is bonded in a distorted trigonal planar geometry to three Al3+ atoms. In the seventeenth O2- site, O2- is bonded in a rectangular see-saw-like geometry to four Al3+ atoms. In the eighteenth O2- site, O2- is bonded in a rectangular see-saw-like geometry to four Al3+ atoms. In the nineteenth O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to four Al3+ atoms. In the twentieth O2- site, O2- is bonded in a distorted trigonal planar geometry to three Al3+ atoms. In the twenty-first O2- site, O2- is bonded in a distorted T-shaped geometry to three Al3+ atoms. In the twenty-second O2- site, O2- is bonded in a distorted trigonal planar geometry to three Al3+ atoms. In the twenty-third O2- site, O2- is bonded in a distorted trigonal planar geometry to three Al3+ atoms. In the twenty-fourth O2- site, O2- is bonded in a distorted trigonal planar geometry to three Al3+ atoms.