DOE OSTI2020
CdAl22O34 crystallizes in the monoclinic P2_1/m space group. The structure is three-dimensional. Cd2+ is bonded in a distorted pentagonal planar geometry to five O2- atoms. There are a spread of Cd–O bond distances ranging from 2.32–2.77 Å. There are fifteen inequivalent Al3+ sites. In the first Al3+ site, Al3+ is bonded to six O2- atoms to form AlO6 octahedra that share corners with six AlO4 tetrahedra and edges with six AlO6 octahedra. There are a spread of Al–O bond distances ranging from 1.90–1.92 Å. In the second Al3+ site, Al3+ is bonded to six O2- atoms to form AlO6 octahedra that share corners with five AlO4 tetrahedra and edges with five AlO6 octahedra. There are a spread of Al–O bond distances ranging from 1.81–2.11 Å. In the third Al3+ site, Al3+ is bonded to six O2- atoms to form AlO6 octahedra that share corners with five AlO4 tetrahedra and edges with five AlO6 octahedra. There are a spread of Al–O bond distances ranging from 1.81–2.08 Å. In the fourth Al3+ site, Al3+ is bonded to six O2- atoms to form AlO6 octahedra that share corners with six AlO4 tetrahedra and edges with six AlO6 octahedra. There is four shorter (1.90 Å) and two longer (1.91 Å) Al–O bond length. In the fifth Al3+ site, Al3+ is bonded to four O2- atoms to form corner-sharing AlO4 tetrahedra. The corner-sharing octahedra tilt angles range from 53–60°. There are a spread of Al–O bond distances ranging from 1.81–1.83 Å. In the sixth Al3+ site, Al3+ is bonded to four O2- atoms to form AlO4 tetrahedra that share corners with six AlO6 octahedra and a cornercorner with one AlO4 tetrahedra. The corner-sharing octahedra tilt angles range from 53–58°. There are a spread of Al–O bond distances ranging from 1.69–1.82 Å. In the seventh Al3+ site, Al3+ is bonded to six O2- atoms to form AlO6 octahedra that share corners with five AlO4 tetrahedra and edges with five AlO6 octahedra. There are a spread of Al–O bond distances ranging from 1.81–2.02 Å. In the eighth Al3+ site, Al3+ is bonded to six O2- atoms to form AlO6 octahedra that share corners with five AlO4 tetrahedra and edges with five AlO6 octahedra. There are a spread of Al–O bond distances ranging from 1.81–2.02 Å. In the ninth Al3+ site, Al3+ is bonded to four O2- atoms to form corner-sharing AlO4 tetrahedra. The corner-sharing octahedra tilt angles range from 53–59°. There are a spread of Al–O bond distances ranging from 1.81–1.84 Å. In the tenth Al3+ site, Al3+ is bonded to six O2- atoms to form AlO6 octahedra that share corners with five AlO4 tetrahedra and edges with five AlO6 octahedra. There are a spread of Al–O bond distances ranging from 1.82–2.04 Å. In the eleventh Al3+ site, Al3+ is bonded to four O2- atoms to form AlO4 tetrahedra that share corners with six AlO6 octahedra and a cornercorner with one AlO4 tetrahedra. The corner-sharing octahedra tilt angles range from 52–55°. There are a spread of Al–O bond distances ranging from 1.77–1.79 Å. In the twelfth Al3+ site, Al3+ is bonded to four O2- atoms to form AlO4 tetrahedra that share corners with six AlO6 octahedra and a cornercorner with one AlO4 tetrahedra. The corner-sharing octahedra tilt angles range from 52–55°. There are a spread of Al–O bond distances ranging from 1.76–1.81 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 53–59°. There is three shorter (1.81 Å) and one longer (1.82 Å) Al–O bond length. In the fourteenth Al3+ site, Al3+ is bonded to six O2- atoms to form AlO6 octahedra that share corners with five AlO4 tetrahedra and edges with five AlO6 octahedra. There are a spread of Al–O bond distances ranging from 1.82–2.05 Å. In the fifteenth Al3+ site, Al3+ is bonded to six O2- atoms to form AlO6 octahedra that share corners with five AlO4 tetrahedra and edges with five AlO6 octahedra. There are a spread of Al–O bond distances ranging from 1.81–2.11 Å. There are twenty-two inequivalent O2- sites. In the first O2- site, O2- is bonded in a trigonal non-coplanar geometry to three 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 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 in a 4-coordinate geometry to one Cd2+ and three Al3+ atoms. In the sixth O2- site, O2- is bonded in a trigonal planar geometry to three 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 3-coordinate geometry to one Cd2+ and three Al3+ atoms. In the ninth O2- site, O2- is bonded in a rectangular see-saw-like geometry to four Al3+ atoms. 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 in a distorted rectangular see-saw-like geometry to four Al3+ atoms. In the twelfth O2- site, O2- is bonded in a rectangular see-saw-like geometry to four Al3+ atoms. 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 trigonal planar geometry to three Al3+ atoms. In the fifteenth O2- site, O2- is bonded in a 3-coordinate geometry to one Cd2+ and two Al3+ atoms. In the sixteenth O2- site, O2- is bonded in a trigonal planar geometry to three Al3+ atoms. In the seventeenth O2- site, O2- is bonded in a 4-coordinate geometry to one Cd2+ and three Al3+ atoms. In the eighteenth O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to four Al3+ atoms. In the nineteenth O2- site, O2- is bonded in a rectangular see-saw-like geometry to four Al3+ atoms. In the twentieth O2- site, O2- is bonded in a rectangular see-saw-like geometry to four Al3+ atoms. In the twenty-first O2- site, O2- is bonded in a trigonal non-coplanar geometry to three Al3+ atoms. In the twenty-second O2- site, O2- is bonded in a linear geometry to two equivalent Al3+ atoms.