CsAl(MoO4)2 crystallizes in the trigonal P-3m1 space group. Cs(1) is bonded to six equivalent O(1) and six equivalent O(2) atoms to form CsO12 cuboctahedra that share edges with six equivalent Cs(1)O12 cuboctahedra, edges with six equivalent Mo(1)O4 tetrahedra, and faces with two equivalent Al(1)O6 octahedra. Mo(1) is bonded to one O(1) and three equivalent O(2) atoms to form MoO4 tetrahedra that share corners with three equivalent Al(1)O6 octahedra and edges with three equivalent Cs(1)O12 cuboctahedra. The corner-sharing octahedral tilt angles are 18°. Al(1) is bonded to six equivalent O(2) atoms to form AlO6 octahedra that share corners with six equivalent Mo(1)O4 tetrahedra and faces with two equivalent Cs(1)O12 cuboctahedra. There are two inequivalent O sites. In the first O site, O(1) is bonded in a single-bond geometry to three equivalent Cs(1) and one Mo(1) atom. In the second O site, O(2) is bonded in a distorted bent 150 degrees geometry to one Cs(1), one Mo(1), and one Al(1) atom.
CsAl(MoO4)2 crystallizes in the trigonal P-3m1 space group. Cs(1) is bonded to six equivalent O(1) and six equivalent O(2) atoms to form CsO12 cuboctahedra that share edges with six equivalent Cs(1)O12 cuboctahedra, edges with six equivalent Mo(1)O4 tetrahedra, and faces with two equivalent Al(1)O6 octahedra. All Cs(1)-O(1) bond lengths are 3.34 Å. All Cs(1)-O(2) bond lengths are 3.38 Å. Mo(1) is bonded to one O(1) and three equivalent O(2) atoms to form MoO4 tetrahedra that share corners with three equivalent Al(1)O6 octahedra and edges with three equivalent Cs(1)O12 cuboctahedra. The corner-sharing octahedral tilt angles are 18°. The Mo(1)-O(1) bond length is 1.75 Å. All Mo(1)-O(2) bond lengths are 1.81 Å. Al(1) is bonded to six equivalent O(2) atoms to form AlO6 octahedra that share corners with six equivalent Mo(1)O4 tetrahedra and faces with two equivalent Cs(1)O12 cuboctahedra. All Al(1)-O(2) bond lengths are 1.91 Å. There are two inequivalent O sites. In the first O site, O(1) is bonded in a single-bond geometry to three equivalent Cs(1) and one Mo(1) atom. In the second O site, O(2) is bonded in a distorted bent 150 degrees geometry to one Cs(1), one Mo(1), and one Al(1) atom.