DOE OSTI2020
GdAl22O34 crystallizes in the triclinic P-1 space group. The structure is three-dimensional. Gd is bonded in a 8-coordinate geometry to eight O atoms. There are a spread of Gd–O bond distances ranging from 2.41–2.87 Å. There are twelve inequivalent Al sites. In the first Al site, Al is bonded to six O 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 Al site, Al is bonded to six O 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 1.82–2.09 Å. In the third Al site, Al is bonded to six O 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 1.81–2.09 Å. In the fourth Al site, Al is bonded to six O 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 fifth Al site, Al is bonded to six O 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 sixth Al site, Al is bonded to four O atoms to form corner-sharing AlO4 tetrahedra. The corner-sharing octahedra tilt angles range from 53–59°. There is two shorter (1.81 Å) and two longer (1.83 Å) Al–O bond length. In the seventh Al site, Al is bonded to four O 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 1.74–1.81 Å. In the eighth Al site, Al is bonded to four O 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 53–57°. There are a spread of Al–O bond distances ranging from 1.73–1.82 Å. In the ninth Al site, Al is bonded to six O 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 1.81–2.06 Å. In the tenth Al site, Al is bonded to six O 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 1.85–1.99 Å. In the eleventh Al site, Al is bonded to six O 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 1.82–2.08 Å. In the twelfth Al site, Al is bonded to four O atoms to form corner-sharing AlO4 tetrahedra. The corner-sharing octahedra tilt angles range from 52–60°. There are a spread of Al–O bond distances ranging from 1.81–1.83 Å. There are seventeen inequivalent O sites. In the first O site, O is bonded in a trigonal non-coplanar geometry to three Al atoms. In the second O site, O is bonded in a rectangular see-saw-like geometry to four Al atoms. In the third O site, O is bonded in a rectangular see-saw-like geometry to four Al atoms. In the fourth O site, O is bonded in a rectangular see-saw-like geometry to four Al atoms. In the fifth O site, O is bonded in a rectangular see-saw-like geometry to four Al atoms. In the sixth O site, O is bonded in a 3-coordinate geometry to one Gd and three Al atoms. In the seventh O site, O is bonded in a distorted trigonal planar geometry to one Gd and three Al atoms. In the eighth O site, O is bonded in a trigonal planar geometry to three Al atoms. In the ninth O site, O is bonded in a trigonal planar geometry to three Al atoms. In the tenth O site, O is bonded in a 3-coordinate geometry to one Gd and two Al atoms. In the eleventh O site, O is bonded in a distorted trigonal planar geometry to one Gd and three Al atoms. In the twelfth O site, O is bonded in a trigonal planar geometry to three Al atoms. In the thirteenth O site, O is bonded in a trigonal planar geometry to three Al atoms. In the fourteenth O site, O is bonded in a rectangular see-saw-like geometry to four Al atoms. In the fifteenth O site, O is bonded in a rectangular see-saw-like geometry to four Al atoms. In the sixteenth O site, O is bonded in a rectangular see-saw-like geometry to four Al atoms. In the seventeenth O site, O is bonded in a rectangular see-saw-like geometry to four Al atoms.