LaSb5O12 crystallizes in the trigonal R-3m space group. La(1) is bonded to six equivalent O(1) and six equivalent O(2) atoms to form LaO12 cuboctahedra that share faces with six equivalent Sb(1)O6 octahedra. There are two inequivalent Sb sites. In the first Sb site, Sb(1) is bonded to two equivalent O(1) and four equivalent O(2) atoms to form SbO6 octahedra that share corners with four equivalent Sb(1)O6 octahedra and faces with two equivalent La(1)O12 cuboctahedra. The corner-sharing octahedral tilt angles are 45°. In the second Sb site, Sb(2) is bonded in a distorted T-shaped geometry to three equivalent O(1) atoms. There are two inequivalent O sites. In the first O site, O(1) is bonded in a 3-coordinate geometry to one La(1), one Sb(1), and one Sb(2) atom. In the second O site, O(2) is bonded in a 3-coordinate geometry to one La(1) and two equivalent Sb(1) atoms.
LaSb5O12 crystallizes in the trigonal R-3m space group. La(1) is bonded to six equivalent O(1) and six equivalent O(2) atoms to form LaO12 cuboctahedra that share faces with six equivalent Sb(1)O6 octahedra. All La(1)-O(1) bond lengths are 2.68 Å. All La(1)-O(2) bond lengths are 2.71 Å. There are two inequivalent Sb sites. In the first Sb site, Sb(1) is bonded to two equivalent O(1) and four equivalent O(2) atoms to form SbO6 octahedra that share corners with four equivalent Sb(1)O6 octahedra and faces with two equivalent La(1)O12 cuboctahedra. The corner-sharing octahedral tilt angles are 45°. Both Sb(1)-O(1) bond lengths are 1.98 Å. All Sb(1)-O(2) bond lengths are 1.98 Å. In the second Sb site, Sb(2) is bonded in a distorted T-shaped geometry to three equivalent O(1) atoms. All Sb(2)-O(1) bond lengths are 1.98 Å. There are two inequivalent O sites. In the first O site, O(1) is bonded in a 3-coordinate geometry to one La(1), one Sb(1), and one Sb(2) atom. In the second O site, O(2) is bonded in a 3-coordinate geometry to one La(1) and two equivalent Sb(1) atoms.