LiCd2Al4O8 crystallizes in the trigonal R-3m space group. Li(1) is bonded to six equivalent O(2) atoms to form distorted LiO6 octahedra that share corners with six equivalent Al(1)O6 octahedra and edges with six equivalent Al(2)O6 octahedra. The corner-sharing octahedral tilt angles are 13°. Cd(1) is bonded in a 4-coordinate geometry to one O(1) and three equivalent O(2) atoms. There are two inequivalent Al sites. In the first Al site, Al(1) is bonded to six equivalent O(2) atoms to form distorted AlO6 octahedra that share corners with six equivalent Li(1)O6 octahedra and edges with six equivalent Al(2)O6 octahedra. The corner-sharing octahedral tilt angles are 13°. In the second Al site, Al(2) is bonded to two equivalent O(1) and four equivalent O(2) atoms to form AlO6 octahedra that share edges with two equivalent Li(1)O6 octahedra, edges with two equivalent Al(1)O6 octahedra, and edges with four equivalent Al(2)O6 octahedra. There are two inequivalent O sites. In the first O site, O(1) is bonded to one Cd(1) and three equivalent Al(2) atoms to form OAl3Cd tetrahedra that share corners with three equivalent O(1)Al3Cd tetrahedra, corners with nine equivalent O(2)LiAl3Cd trigonal bipyramids, and edges with three equivalent O(2)LiAl3Cd trigonal bipyramids. In the second O site, O(2) is bonded to one Li(1), one Cd(1), one Al(1), and two equivalent Al(2) atoms to form distorted OLiAl3Cd trigonal bipyramids that share corners with three equivalent O(1)Al3Cd tetrahedra, corners with six equivalent O(2)LiAl3Cd trigonal bipyramids,  an edgeedge with one O(1)Al3Cd tetrahedra, and edges with six equivalent O(2)LiAl3Cd trigonal bipyramids.
LiCd2Al4O8 crystallizes in the trigonal R-3m space group. Li(1) is bonded to six equivalent O(2) atoms to form distorted LiO6 octahedra that share corners with six equivalent Al(1)O6 octahedra and edges with six equivalent Al(2)O6 octahedra. The corner-sharing octahedral tilt angles are 13°. All Li(1)-O(2) bond lengths are 2.24 Å. Cd(1) is bonded in a 4-coordinate geometry to one O(1) and three equivalent O(2) atoms. The Cd(1)-O(1) bond length is 2.10 Å. All Cd(1)-O(2) bond lengths are 2.25 Å. There are two inequivalent Al sites. In the first Al site, Al(1) is bonded to six equivalent O(2) atoms to form distorted AlO6 octahedra that share corners with six equivalent Li(1)O6 octahedra and edges with six equivalent Al(2)O6 octahedra. The corner-sharing octahedral tilt angles are 13°. All Al(1)-O(2) bond lengths are 2.10 Å. In the second Al site, Al(2) is bonded to two equivalent O(1) and four equivalent O(2) atoms to form AlO6 octahedra that share edges with two equivalent Li(1)O6 octahedra, edges with two equivalent Al(1)O6 octahedra, and edges with four equivalent Al(2)O6 octahedra. Both Al(2)-O(1) bond lengths are 1.89 Å. All Al(2)-O(2) bond lengths are 2.00 Å. There are two inequivalent O sites. In the first O site, O(1) is bonded to one Cd(1) and three equivalent Al(2) atoms to form OAl3Cd tetrahedra that share corners with three equivalent O(1)Al3Cd tetrahedra, corners with nine equivalent O(2)LiAl3Cd trigonal bipyramids, and edges with three equivalent O(2)LiAl3Cd trigonal bipyramids. In the second O site, O(2) is bonded to one Li(1), one Cd(1), one Al(1), and two equivalent Al(2) atoms to form distorted OLiAl3Cd trigonal bipyramids that share corners with three equivalent O(1)Al3Cd tetrahedra, corners with six equivalent O(2)LiAl3Cd trigonal bipyramids,  an edgeedge with one O(1)Al3Cd tetrahedra, and edges with six equivalent O(2)LiAl3Cd trigonal bipyramids.