KMgAl(MoO4)2 crystallizes in the trigonal P3m1 space group. K(1) is bonded to three equivalent O(1), three equivalent O(2), three equivalent O(3), and three equivalent O(4) atoms to form distorted KO12 cuboctahedra that share edges with six equivalent K(1)O12 cuboctahedra, edges with three equivalent Mo(1)O4 tetrahedra, edges with three equivalent Mo(2)O4 tetrahedra, and faces with two equivalent Al(1)O6 octahedra. Mg(1) is bonded in a single-bond geometry to one O(4) atom. There are two inequivalent Mo sites. In the first Mo site, Mo(1) is bonded to one O(3) and three equivalent O(2) atoms to form distorted MoO4 tetrahedra that share corners with three equivalent Al(1)O6 octahedra and edges with three equivalent K(1)O12 cuboctahedra. The corner-sharing octahedral tilt angles are 3°. In the second Mo site, Mo(2) is bonded to one O(4) and three equivalent O(1) atoms to form MoO4 tetrahedra that share corners with three equivalent Al(1)O6 octahedra and edges with three equivalent K(1)O12 cuboctahedra. The corner-sharing octahedral tilt angles are 12°. Al(1) is bonded to three equivalent O(1) and three equivalent O(2) atoms to form AlO6 octahedra that share corners with three equivalent Mo(1)O4 tetrahedra, corners with three equivalent Mo(2)O4 tetrahedra, and faces with two equivalent K(1)O12 cuboctahedra. There are four inequivalent O sites. In the first O site, O(1) is bonded in a 2-coordinate geometry to one K(1), one Mo(2), and one Al(1) atom. In the second O site, O(2) is bonded in a 2-coordinate geometry to one K(1), one Mo(1), and one Al(1) atom. In the third O site, O(3) is bonded in a single-bond geometry to three equivalent K(1) and one Mo(1) atom. In the fourth O site, O(4) is bonded in a linear geometry to three equivalent K(1), one Mg(1), and one Mo(2) atom.
KMgAl(MoO4)2 crystallizes in the trigonal P3m1 space group. K(1) is bonded to three equivalent O(1), three equivalent O(2), three equivalent O(3), and three equivalent O(4) atoms to form distorted KO12 cuboctahedra that share edges with six equivalent K(1)O12 cuboctahedra, edges with three equivalent Mo(1)O4 tetrahedra, edges with three equivalent Mo(2)O4 tetrahedra, and faces with two equivalent Al(1)O6 octahedra. All K(1)-O(1) bond lengths are 2.81 Å. All K(1)-O(2) bond lengths are 2.79 Å. All K(1)-O(3) bond lengths are 3.23 Å. All K(1)-O(4) bond lengths are 3.22 Å. Mg(1) is bonded in a single-bond geometry to one O(4) atom. The Mg(1)-O(4) bond length is 1.99 Å. There are two inequivalent Mo sites. In the first Mo site, Mo(1) is bonded to one O(3) and three equivalent O(2) atoms to form distorted MoO4 tetrahedra that share corners with three equivalent Al(1)O6 octahedra and edges with three equivalent K(1)O12 cuboctahedra. The corner-sharing octahedral tilt angles are 3°. The Mo(1)-O(3) bond length is 1.81 Å. All Mo(1)-O(2) bond lengths are 1.95 Å. In the second Mo site, Mo(2) is bonded to one O(4) and three equivalent O(1) atoms to form MoO4 tetrahedra that share corners with three equivalent Al(1)O6 octahedra and edges with three equivalent K(1)O12 cuboctahedra. The corner-sharing octahedral tilt angles are 12°. The Mo(2)-O(4) bond length is 1.85 Å. All Mo(2)-O(1) bond lengths are 1.80 Å. Al(1) is bonded to three equivalent O(1) and three equivalent O(2) atoms to form AlO6 octahedra that share corners with three equivalent Mo(1)O4 tetrahedra, corners with three equivalent Mo(2)O4 tetrahedra, and faces with two equivalent K(1)O12 cuboctahedra. All Al(1)-O(1) bond lengths are 2.03 Å. All Al(1)-O(2) bond lengths are 1.81 Å. There are four inequivalent O sites. In the first O site, O(1) is bonded in a 2-coordinate geometry to one K(1), one Mo(2), and one Al(1) atom. In the second O site, O(2) is bonded in a 2-coordinate geometry to one K(1), one Mo(1), and one Al(1) atom. In the third O site, O(3) is bonded in a single-bond geometry to three equivalent K(1) and one Mo(1) atom. In the fourth O site, O(4) is bonded in a linear geometry to three equivalent K(1), one Mg(1), and one Mo(2) atom.