DOI: 10.17188/1263312
title: Materials Data on Al2CuO4 by Materials Project

description: CuAl2O4 is Spinel-like structured and crystallizes in the trigonal R3m space group. The structure is three-dimensional. there are eight inequivalent Cu2+ sites. In the first Cu2+ site, Cu2+ is bonded to four O2- atoms to form CuO4 tetrahedra that share corners with three equivalent CuO6 octahedra and corners with nine AlO6 octahedra. The corner-sharing octahedra tilt angles range from 56–63°. There is three shorter (1.95 Å) and one longer (1.97 Å) Cu–O bond length. In the second Cu2+ site, Cu2+ is bonded to six O2- atoms to form CuO6 octahedra that share corners with three equivalent CuO4 tetrahedra, corners with three equivalent AlO4 tetrahedra, and edges with six AlO6 octahedra. There are three shorter (2.00 Å) and three longer (2.10 Å) Cu–O bond lengths. In the third Cu2+ site, Cu2+ is bonded to four O2- atoms to form CuO4 tetrahedra that share corners with three equivalent CuO6 octahedra and corners with nine AlO6 octahedra. The corner-sharing octahedra tilt angles range from 57–62°. There is three shorter (1.95 Å) and one longer (1.97 Å) Cu–O bond length. In the fourth Cu2+ site, Cu2+ is bonded to six O2- atoms to form CuO6 octahedra that share corners with three equivalent CuO4 tetrahedra, corners with three equivalent AlO4 tetrahedra, and edges with six AlO6 octahedra. There are three shorter (1.99 Å) and three longer (2.11 Å) Cu–O bond lengths. In the fifth Cu2+ site, Cu2+ is bonded to four O2- atoms to form CuO4 tetrahedra that share corners with three equivalent CuO6 octahedra and corners with nine AlO6 octahedra. The corner-sharing octahedra tilt angles range from 57–62°. There is three shorter (1.93 Å) and one longer (1.98 Å) Cu–O bond length. In the sixth Cu2+ site, Cu2+ is bonded to six O2- atoms to form CuO6 octahedra that share corners with three equivalent CuO4 tetrahedra, corners with three equivalent AlO4 tetrahedra, and edges with six AlO6 octahedra. There are three shorter (1.99 Å) and three longer (2.12 Å) Cu–O bond lengths. In the seventh Cu2+ site, Cu2+ is bonded to four O2- atoms to form CuO4 tetrahedra that share corners with twelve AlO6 octahedra. The corner-sharing octahedra tilt angles range from 59–60°. There is one shorter (1.95 Å) and three longer (1.97 Å) Cu–O bond length. In the eighth Cu2+ site, Cu2+ is bonded to four O2- atoms to form CuO4 tetrahedra that share corners with twelve AlO6 octahedra. The corner-sharing octahedra tilt angles range from 60–62°. There are three shorter (1.99 Å) and one longer (2.09 Å) Cu–O bond lengths. There are eight inequivalent Al3+ sites. In the first Al3+ site, Al3+ is bonded to six O2- atoms to form AlO6 octahedra that share corners with three CuO4 tetrahedra, corners with three AlO4 tetrahedra, edges with two CuO6 octahedra, and edges with four equivalent AlO6 octahedra. There are a spread of Al–O bond distances ranging from 1.89–2.00 Å. In the second Al3+ site, Al3+ is bonded to six O2- atoms to form AlO6 octahedra that share corners with three CuO4 tetrahedra, corners with three AlO4 tetrahedra, edges with two CuO6 octahedra, and edges with four equivalent AlO6 octahedra. There are a spread of Al–O bond distances ranging from 1.89–2.02 Å. In the third Al3+ site, Al3+ is bonded to six O2- atoms to form AlO6 octahedra that share a cornercorner with one AlO4 tetrahedra, corners with five CuO4 tetrahedra, an edgeedge with one CuO6 octahedra, and edges with five AlO6 octahedra. There are a spread of Al–O bond distances ranging from 1.90–2.05 Å. In the fourth Al3+ site, Al3+ is bonded to four O2- atoms to form AlO4 tetrahedra that share corners with three equivalent CuO6 octahedra and corners with nine AlO6 octahedra. The corner-sharing octahedra tilt angles range from 56–62°. There is three shorter (1.84 Å) and one longer (1.89 Å) Al–O bond length. In the fifth Al3+ site, Al3+ is bonded to six O2- atoms to form AlO6 octahedra that share corners with six CuO4 tetrahedra and edges with six AlO6 octahedra. There is three shorter (1.92 Å) and three longer (1.93 Å) Al–O bond length. In the sixth Al3+ site, Al3+ is bonded to four O2- atoms to form AlO4 tetrahedra that share corners with three equivalent CuO6 octahedra and corners with nine AlO6 octahedra. The corner-sharing octahedra tilt angles range from 54–62°. All Al–O bond lengths are 1.84 Å. In the seventh Al3+ site, Al3+ is bonded to six O2- atoms to form AlO6 octahedra that share corners with two equivalent AlO4 tetrahedra, corners with four CuO4 tetrahedra, an edgeedge with one CuO6 octahedra, and edges with five AlO6 octahedra. There are a spread of Al–O bond distances ranging from 1.88–1.99 Å. In the eighth Al3+ site, Al3+ is bonded to four O2- atoms to form AlO4 tetrahedra that share corners with three equivalent CuO6 octahedra and corners with nine AlO6 octahedra. The corner-sharing octahedra tilt angles range from 54–61°. There is three shorter (1.81 Å) and one longer (1.89 Å) Al–O bond length. There are sixteen inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to two Cu2+ and two equivalent Al3+ atoms. In the second O2- site, O2- is bonded to one Cu2+ and three equivalent Al3+ atoms to form distorted corner-sharing OAl3Cu trigonal pyramids. In the third O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to two Cu2+ and two equivalent Al3+ atoms. In the fourth O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to one Cu2+ and three Al3+ atoms. In the fifth O2- site, O2- is bonded in a distorted trigonal pyramidal geometry to one Cu2+ and three equivalent Al3+ atoms. In the sixth O2- site, O2- is bonded to four Al3+ atoms to form distorted corner-sharing OAl4 trigonal pyramids. In the seventh O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to two Cu2+ and two equivalent Al3+ atoms. In the eighth O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to one Cu2+ and three Al3+ atoms. In the ninth O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to four Al3+ atoms. In the tenth O2- site, O2- is bonded to one Cu2+ and three equivalent Al3+ atoms to form distorted corner-sharing OAl3Cu trigonal pyramids. In the eleventh O2- site, O2- is bonded to one Cu2+ and three Al3+ atoms to form a mixture of distorted corner and edge-sharing OAl3Cu tetrahedra. In the twelfth O2- site, O2- is bonded to one Cu2+ and three Al3+ atoms to form a mixture of distorted corner and edge-sharing OAl3Cu tetrahedra. In the thirteenth O2- site, O2- is bonded to one Cu2+ and three equivalent Al3+ atoms to form a mixture of distorted corner and edge-sharing OAl3Cu trigonal pyramids. In the fourteenth O2- site, O2- is bonded in a rectangular see-saw-like geometry to four Al3+ atoms. In the fifteenth O2- site, O2- is bonded in a rectangular see-saw-like geometry to one Cu2+ and three Al3+ atoms. In the sixteenth O2- site, O2- is bonded to one Cu2+ and three equivalent Al3+ atoms to form corner-sharing OAl3Cu tetrahedra.