Materials Data on MgAl10O16 by Materials Project

MgAl10O16 is beta indium sulfide-derived structured and crystallizes in the trigonal R3m space group. The structure is three-dimensional. Mg2+ is bonded to four O2- atoms to form MgO4 tetrahedra that share corners with twelve AlO6 octahedra. The corner-sharing octahedra tilt angles range from 57–61°. There is three shorter (1.94 Å) and one longer (1.99 Å) Mg–O bond length. There are six 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 53–58°. There is three shorter (1.76 Å) and one longer (1.80 Å) Al–O bond length. In the second Al3+ site, Al3+ is bonded to six O2- atoms to form AlO6 octahedra that share a cornercorner with one MgO4 tetrahedra, corners with five AlO4 tetrahedra, and edges with five AlO6 octahedra. There are a spread of Al–O bond distances ranging from 1.85–2.04 Å. In the third Al3+ site, Al3+ is bonded to four O2- atoms to form corner-sharing AlO4 tetrahedra. The corner-sharing octahedra tilt angles range from 55–60°. There is one shorter (1.82 Å) and three longer (1.86 Å) Al–O bond length. In the fourth Al3+ site, Al3+ is bonded to six O2- atoms to form AlO6 octahedra that share corners with two equivalent MgO4 tetrahedra, corners with four AlO4 tetrahedra, and edges with five AlO6 octahedra. There are a spread of Al–O bond distances ranging from 1.87–2.01 Å. In the fifth Al3+ site, Al3+ is bonded to six O2- atoms to form AlO6 octahedra that share corners with three equivalent MgO4 tetrahedra, corners with three equivalent AlO4 tetrahedra, and edges with six AlO6 octahedra. There is three shorter (1.86 Å) and three longer (1.96 Å) Al–O bond length. 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 55–60°. There is three shorter (1.77 Å) and one longer (1.88 Å) Al–O bond length. There are eight 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 distorted trigonal planar geometry to three Al3+ atoms. In the third O2- site, O2- is bonded to four Al3+ atoms to form distorted edge-sharing OAl4 trigonal pyramids. In the fourth O2- site, O2- is bonded to one Mg2+ and three Al3+ atoms to form distorted OMgAl3 tetrahedra that share corners with two equivalent OMgAl3 tetrahedra, edges with two equivalent OMgAl3 tetrahedra, and an edgeedge with one OAl4 trigonal pyramid. In the fifth O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to one Mg2+ and three equivalent Al3+ atoms. In the sixth O2- site, O2- is bonded in a distorted tetrahedral geometry to four Al3+ atoms. In the seventh O2- site, O2- is bonded in a 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.