Ca5Sb3 crystallizes in the hexagonal P6_3/mcm space group. There are two inequivalent Ca sites. In the first Ca site, Ca(1) is bonded to six equivalent Sb(1) atoms to form a mixture of distorted corner, edge, and face-sharing CaSb6 octahedra. The corner-sharing octahedral tilt angles are 36°. In the second Ca site, Ca(2) is bonded in a 5-coordinate geometry to five equivalent Sb(1) atoms. Sb(1) is bonded in a 9-coordinate geometry to four equivalent Ca(1) and five equivalent Ca(2) atoms.
Ca5Sb3 crystallizes in the hexagonal P6_3/mcm space group. There are two inequivalent Ca sites. In the first Ca site, Ca(1) is bonded to six equivalent Sb(1) atoms to form a mixture of distorted corner, edge, and face-sharing CaSb6 octahedra. The corner-sharing octahedral tilt angles are 36°. All Ca(1)-Sb(1) bond lengths are 3.30 Å. In the second Ca site, Ca(2) is bonded in a 5-coordinate geometry to five equivalent Sb(1) atoms. There are a spread of Ca(2)-Sb(1) bond distances ranging from 3.09-3.72 Å. Sb(1) is bonded in a 9-coordinate geometry to four equivalent Ca(1) and five equivalent Ca(2) atoms.