Ba2Cd2Sb3 crystallizes in the monoclinic C2/m space group. There are two inequivalent Ba sites. In the first Ba site, Ba(1) is bonded to one Sb(2), two equivalent Sb(1), and three equivalent Sb(3) atoms to form distorted BaSb6 octahedra that share corners with three equivalent Cd(1)Ba2Sb4 tetrahedra, corners with four equivalent Cd(2)BaSb4 tetrahedra, edges with four equivalent Ba(1)Sb6 octahedra, edges with two equivalent Cd(2)BaSb4 tetrahedra, and edges with three equivalent Cd(1)Ba2Sb4 tetrahedra. In the second Ba site, Ba(2) is bonded in a 10-coordinate geometry to one Cd(2), two equivalent Cd(1), three equivalent Sb(2), and four equivalent Sb(1) atoms. There are two inequivalent Cd sites. In the first Cd site, Cd(1) is bonded to two equivalent Ba(2), one Sb(1), one Sb(2), and two equivalent Sb(3) atoms to form distorted CdBa2Sb4 tetrahedra that share corners with three equivalent Ba(1)Sb6 octahedra, corners with two equivalent Cd(2)BaSb4 tetrahedra, edges with three equivalent Ba(1)Sb6 octahedra, edges with two equivalent Cd(1)Ba2Sb4 tetrahedra, and faces with two equivalent Cd(2)BaSb4 tetrahedra. The corner-sharing octahedral tilt angles range from 19-50°. In the second Cd site, Cd(2) is bonded to one Ba(2), two equivalent Sb(2), and two equivalent Sb(3) atoms to form distorted CdBaSb4 tetrahedra that share corners with four equivalent Ba(1)Sb6 octahedra, corners with two equivalent Cd(1)Ba2Sb4 tetrahedra, corners with two equivalent Cd(2)BaSb4 tetrahedra, edges with two equivalent Ba(1)Sb6 octahedra,  an edgeedge with one Cd(2)BaSb4 tetrahedra, and faces with two equivalent Cd(1)Ba2Sb4 tetrahedra. The corner-sharing octahedral tilt angles range from 26-57°. There are three inequivalent Sb sites. In the first Sb site, Sb(1) is bonded in a 8-coordinate geometry to two equivalent Ba(1), four equivalent Ba(2), one Cd(1), and one Sb(1) atom. In the second Sb site, Sb(2) is bonded in a 7-coordinate geometry to one Ba(1), three equivalent Ba(2), one Cd(1), and two equivalent Cd(2) atoms. In the third Sb site, Sb(3) is bonded to three equivalent Ba(1), two equivalent Cd(1), and two equivalent Cd(2) atoms to form distorted edge-sharing SbBa3Cd4 pentagonal bipyramids.
Ba2Cd2Sb3 crystallizes in the monoclinic C2/m space group. There are two inequivalent Ba sites. In the first Ba site, Ba(1) is bonded to one Sb(2), two equivalent Sb(1), and three equivalent Sb(3) atoms to form distorted BaSb6 octahedra that share corners with three equivalent Cd(1)Ba2Sb4 tetrahedra, corners with four equivalent Cd(2)BaSb4 tetrahedra, edges with four equivalent Ba(1)Sb6 octahedra, edges with two equivalent Cd(2)BaSb4 tetrahedra, and edges with three equivalent Cd(1)Ba2Sb4 tetrahedra. The Ba(1)-Sb(2) bond length is 3.50 Å. Both Ba(1)-Sb(1) bond lengths are 3.55 Å. All Ba(1)-Sb(3) bond lengths are 3.50 Å. In the second Ba site, Ba(2) is bonded in a 10-coordinate geometry to one Cd(2), two equivalent Cd(1), three equivalent Sb(2), and four equivalent Sb(1) atoms. The Ba(2)-Cd(2) bond length is 3.82 Å. Both Ba(2)-Cd(1) bond lengths are 3.73 Å. There are two shorter (3.58 Å) and one longer (3.66 Å) Ba(2)-Sb(2) bond length. There are two shorter (3.65 Å) and two longer (3.77 Å) Ba(2)-Sb(1) bond lengths. There are two inequivalent Cd sites. In the first Cd site, Cd(1) is bonded to two equivalent Ba(2), one Sb(1), one Sb(2), and two equivalent Sb(3) atoms to form distorted CdBa2Sb4 tetrahedra that share corners with three equivalent Ba(1)Sb6 octahedra, corners with two equivalent Cd(2)BaSb4 tetrahedra, edges with three equivalent Ba(1)Sb6 octahedra, edges with two equivalent Cd(1)Ba2Sb4 tetrahedra, and faces with two equivalent Cd(2)BaSb4 tetrahedra. The corner-sharing octahedral tilt angles range from 19-50°. The Cd(1)-Sb(1) bond length is 3.00 Å. The Cd(1)-Sb(2) bond length is 2.93 Å. Both Cd(1)-Sb(3) bond lengths are 2.92 Å. In the second Cd site, Cd(2) is bonded to one Ba(2), two equivalent Sb(2), and two equivalent Sb(3) atoms to form distorted CdBaSb4 tetrahedra that share corners with four equivalent Ba(1)Sb6 octahedra, corners with two equivalent Cd(1)Ba2Sb4 tetrahedra, corners with two equivalent Cd(2)BaSb4 tetrahedra, edges with two equivalent Ba(1)Sb6 octahedra,  an edgeedge with one Cd(2)BaSb4 tetrahedra, and faces with two equivalent Cd(1)Ba2Sb4 tetrahedra. The corner-sharing octahedral tilt angles range from 26-57°. Both Cd(2)-Sb(2) bond lengths are 2.93 Å. There is one shorter (2.91 Å) and one longer (3.06 Å) Cd(2)-Sb(3) bond length. There are three inequivalent Sb sites. In the first Sb site, Sb(1) is bonded in a 8-coordinate geometry to two equivalent Ba(1), four equivalent Ba(2), one Cd(1), and one Sb(1) atom. The Sb(1)-Sb(1) bond length is 2.86 Å. In the second Sb site, Sb(2) is bonded in a 7-coordinate geometry to one Ba(1), three equivalent Ba(2), one Cd(1), and two equivalent Cd(2) atoms. In the third Sb site, Sb(3) is bonded to three equivalent Ba(1), two equivalent Cd(1), and two equivalent Cd(2) atoms to form distorted edge-sharing SbBa3Cd4 pentagonal bipyramids.