Materials Data on Al2FeO4 by Materials Project
FeAl2O4 is Spinel-like structured and crystallizes in the triclinic P1 space group. The structure is three-dimensional. there are six inequivalent Fe2+ sites. In the first Fe2+ site, Fe2+ is bonded to four O2- atoms to form FeO4 tetrahedra that share corners with three equivalent FeO6 octahedra and corners with nine AlO6 octahedra. The corner-sharing octahedra tilt angles range from 55–67°. There are a spread of Fe–O bond distances ranging from 1.97–2.03 Å. In the second Fe2+ site, Fe2+ is bonded to six O2- atoms to form FeO6 octahedra that share corners with three equivalent FeO4 tetrahedra, corners with three equivalent AlO4 tetrahedra, and edges with six AlO6 octahedra. There are a spread of Fe–O bond distances ranging from 2.06–2.18 Å. In the third Fe2+ site, Fe2+ is bonded to four O2- atoms to form FeO4 tetrahedra that share corners with twelve AlO6 octahedra. The corner-sharing octahedra tilt angles range from 57–61°. There is one shorter (1.98 Å) and three longer (2.01 Å) Fe–O bond length. In the fourth Fe2+ site, Fe2+ is bonded to four O2- atoms to form FeO4 tetrahedra that share corners with twelve AlO6 octahedra. The corner-sharing octahedra tilt angles range from 59–61°. There are one shorter (2.00 Å) and three longer (2.01 Å) Fe–O bond lengths. In the fifth Fe2+ site, Fe2+ is bonded to four O2- atoms to form FeO4 tetrahedra that share corners with twelve AlO6 octahedra. The corner-sharing octahedra tilt angles range from 58–63°. There are a spread of Fe–O bond distances ranging from 2.01–2.06 Å. In the sixth Fe2+ site, Fe2+ is bonded to four O2- atoms to form FeO4 tetrahedra that share corners with twelve AlO6 octahedra. The corner-sharing octahedra tilt angles range from 59–63°. There are a spread of Fe–O bond distances ranging from 2.00–2.07 Å. There are twelve inequivalent Al3+ sites. In the first Al3+ site, Al3+ is bonded to six O2- atoms to form AlO6 octahedra that share a cornercorner with one AlO4 tetrahedra, corners with five FeO4 tetrahedra, an edgeedge with one FeO6 octahedra, and edges with five AlO6 octahedra. There are a spread of Al–O bond distances ranging from 1.89–2.08 Å. In the second Al3+ site, Al3+ is bonded to six O2- atoms to form AlO6 octahedra that share corners with six FeO4 tetrahedra and edges with six AlO6 octahedra. There are a spread of Al–O bond distances ranging from 1.93–1.95 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 FeO4 tetrahedra, an edgeedge with one FeO6 octahedra, and edges with five AlO6 octahedra. There are a spread of Al–O bond distances ranging from 1.88–2.11 Å. In the fourth Al3+ site, Al3+ is bonded to six O2- atoms to form AlO6 octahedra that share corners with six FeO4 tetrahedra and edges with six AlO6 octahedra. There are a spread of Al–O bond distances ranging from 1.92–1.95 Å. In the fifth Al3+ site, Al3+ is bonded to six O2- atoms to form AlO6 octahedra that share a cornercorner with one AlO4 tetrahedra, corners with five FeO4 tetrahedra, an edgeedge with one FeO6 octahedra, and edges with five AlO6 octahedra. There are a spread of Al–O bond distances ranging from 1.88–2.09 Å. In the sixth Al3+ site, Al3+ is bonded to six O2- atoms to form AlO6 octahedra that share corners with six FeO4 tetrahedra and edges with six AlO6 octahedra. There is two shorter (1.93 Å) and four longer (1.95 Å) Al–O bond length. 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 FeO4 tetrahedra, an edgeedge with one FeO6 octahedra, and edges with five AlO6 octahedra. There are a spread of Al–O bond distances ranging from 1.92–2.01 Å. In the eighth Al3+ site, Al3+ is bonded to six O2- atoms to form AlO6 octahedra that share corners with six FeO4 tetrahedra and edges with six AlO6 octahedra. There is five shorter (1.93 Å) and one longer (1.94 Å) Al–O bond length. In the ninth Al3+ site, Al3+ is bonded to six O2- atoms to form AlO6 octahedra that share corners with six FeO4 tetrahedra and edges with six AlO6 octahedra. There are a spread of Al–O bond distances ranging from 1.93–1.95 Å. In the tenth Al3+ site, Al3+ is bonded to six O2- atoms to form AlO6 octahedra that share corners with two equivalent AlO4 tetrahedra, corners with four FeO4 tetrahedra, an edgeedge with one FeO6 octahedra, and edges with five AlO6 octahedra. There are a spread of Al–O bond distances ranging from 1.91–2.01 Å. In the eleventh Al3+ site, Al3+ is bonded to six O2- atoms to form AlO6 octahedra that share corners with two equivalent AlO4 tetrahedra, corners with four FeO4 tetrahedra, an edgeedge with one FeO6 octahedra, and edges with five AlO6 octahedra. There are a spread of Al–O bond distances ranging from 1.92–1.99 Å. In the twelfth Al3+ site, Al3+ is bonded to four O2- atoms to form AlO4 tetrahedra that share corners with three equivalent FeO6 octahedra and corners with nine AlO6 octahedra. The corner-sharing octahedra tilt angles range from 54–63°. There is two shorter (1.83 Å) and two longer (1.84 Å) Al–O bond length. There are twenty-four inequivalent O2- sites. In the first O2- site, O2- is bonded to two Fe2+ and two Al3+ atoms to form a mixture of distorted edge and corner-sharing OAl2Fe2 trigonal pyramids. In the second O2- site, O2- is bonded to one Fe2+ and three Al3+ atoms to form distorted OAl3Fe trigonal pyramids that share corners with nine OAl3Fe tetrahedra and edges with two OAl2Fe2 trigonal pyramids. In the third O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to two Fe2+ and two Al3+ atoms. In the fourth O2- site, O2- is bonded to two Fe2+ and two Al3+ atoms to form distorted OAl2Fe2 trigonal pyramids that share corners with four OAl3Fe tetrahedra, corners with two OAl3Fe trigonal pyramids, and edges with two OAl2Fe2 trigonal pyramids. In the fifth O2- site, O2- is bonded to one Fe2+ and three Al3+ atoms to form a mixture of distorted edge and corner-sharing OAl3Fe tetrahedra. In the sixth O2- site, O2- is bonded to one Fe2+ and three Al3+ atoms to form distorted OAl3Fe tetrahedra that share corners with six OAl3Fe tetrahedra, corners with five OAl2Fe2 trigonal pyramids, and edges with two OAl3Fe tetrahedra. In the seventh O2- site, O2- is bonded to one Fe2+ and three Al3+ atoms to form distorted OAl3Fe tetrahedra that share corners with six OAl3Fe tetrahedra, corners with four OAl2Fe2 trigonal pyramids, and edges with two OAl3Fe tetrahedra. In the eighth O2- site, O2- is bonded to one Fe2+ and three Al3+ atoms to form a mixture of distorted edge and corner-sharing OAl3Fe trigonal pyramids. In the ninth O2- site, O2- is bonded to one Fe2+ and three Al3+ atoms to form a mixture of distorted edge and corner-sharing OAl3Fe tetrahedra. In the tenth O2- site, O2- is bonded in a rectangular see-saw-like geometry to four Al3+ atoms. In the eleventh O2- site, O2- is bonded to one Fe2+ and three Al3+ atoms to form a mixture of distorted edge and corner-sharing OAl3Fe tetrahedra. In the twelfth O2- site, O2- is bonded to one Fe2+ and three Al3+ atoms to form distorted OAl3Fe tetrahedra that share corners with six OAl3Fe tetrahedra, corners with five OAl2Fe2 trigonal pyramids, and edges with two OAl3Fe tetrahedra. In the thirteenth O2- site, O2- is bonded to one Fe2+ and three Al3+ atoms to form a mixture of distorted edge and corner-sharing OAl3Fe tetrahedra. In the fourteenth O2- site, O2- is bonded to one Fe2+ and three Al3+ atoms to form a mixture of distorted edge and corner-sharing OAl3Fe tetrahedra. In the fifteenth O2- site, O2- is bonded to one Fe2+ and three Al3+ atoms to form a mixture of distorted edge and corner-sharing OAl3Fe tetrahedra. In the sixteenth O2- site, O2- is bonded to one Fe2+ and three Al3+ atoms to form distorted OAl3Fe trigonal pyramids that share corners with three equivalent OAl3Fe tetrahedra, corners with two OAl2Fe2 trigonal pyramids, and edges with three OAl3Fe tetrahedra. In the seventeenth O2- site, O2- is bonded to one Fe2+ and three Al3+ atoms to form a mixture of distorted edge and corner-sharing OAl3Fe tetrahedra. In the eighteenth O2- site, O2- is bonded to one Fe2+ and three Al3+ atoms to form a mixture of distorted edge and corner-sharing OAl3Fe tetrahedra. In the nineteenth O2- site, O2- is bonded to one Fe2+ and three Al3+ atoms to form a mixture of distorted edge and corner-sharing OAl3Fe tetrahedra. In the twentieth O2- site, O2- is bonded to one Fe2+ and three Al3+ atoms to form a mixture of distorted edge and corner-sharing OAl3Fe tetrahedra. In the twenty-first O2- site, O2- is bonded in a rectangular see-saw-like geometry to one Fe2+ and three Al3+ atoms. In the twenty-second O2- site, O2- is bonded in a rectangular see-saw-like geometry to one Fe2+ and three Al3+ atoms. In the twenty-third O2- site, O2- is bonded to one Fe2+ and three Al3+ atoms to form corner-sharing OAl3Fe tetrahedra. In the twenty-fourth O2- site, O2- is bonded in a rectangular see-saw-like geometry to one Fe2+ and three Al3+ atoms.