La2VCo16 crystallizes in the trigonal R3m space group. There are two inequivalent La sites. In the first La site, La(1) is bonded in a 19-coordinate geometry to one Co(5), three equivalent Co(1), three equivalent Co(4), six equivalent Co(2), and six equivalent Co(3) atoms. In the second La site, La(2) is bonded in a 19-coordinate geometry to one V(1), three equivalent Co(2), three equivalent Co(4), six equivalent Co(1), and six equivalent Co(3) atoms. V(1) is bonded in a 14-coordinate geometry to one La(2), one Co(5), three equivalent Co(1), three equivalent Co(4), and six equivalent Co(3) atoms. There are five inequivalent Co sites. In the first Co site, Co(1) is bonded to one La(1), two equivalent La(2), one V(1), two equivalent Co(2), two equivalent Co(4), and four equivalent Co(3) atoms to form CoLa3VCo8 cuboctahedra that share corners with two equivalent Co(1)La3VCo8 cuboctahedra, corners with five equivalent Co(4)La2VCo9 cuboctahedra, corners with eight equivalent Co(3)La2VCo9 cuboctahedra, corners with eight equivalent Co(2)La3Co9 cuboctahedra,  an edgeedge with one Co(2)La3Co9 cuboctahedra, edges with two equivalent Co(3)La2VCo9 cuboctahedra, edges with three equivalent Co(4)La2VCo9 cuboctahedra, edges with four equivalent Co(1)La3VCo8 cuboctahedra, faces with three equivalent Co(4)La2VCo9 cuboctahedra, faces with three equivalent Co(2)La3Co9 cuboctahedra, faces with four equivalent Co(1)La3VCo8 cuboctahedra, and faces with ten equivalent Co(3)La2VCo9 cuboctahedra. In the second Co site, Co(2) is bonded to one La(2), two equivalent La(1), one Co(5), two equivalent Co(1), two equivalent Co(4), and four equivalent Co(3) atoms to form CoLa3Co9 cuboctahedra that share corners with two equivalent Co(2)La3Co9 cuboctahedra, corners with five equivalent Co(4)La2VCo9 cuboctahedra, corners with eight equivalent Co(3)La2VCo9 cuboctahedra, corners with eight equivalent Co(1)La3VCo8 cuboctahedra,  an edgeedge with one Co(1)La3VCo8 cuboctahedra, edges with two equivalent Co(3)La2VCo9 cuboctahedra, edges with three equivalent Co(4)La2VCo9 cuboctahedra, edges with four equivalent Co(2)La3Co9 cuboctahedra, faces with three equivalent Co(4)La2VCo9 cuboctahedra, faces with three equivalent Co(1)La3VCo8 cuboctahedra, faces with four equivalent Co(2)La3Co9 cuboctahedra, and faces with ten equivalent Co(3)La2VCo9 cuboctahedra. In the third Co site, Co(3) is bonded to one La(1), one La(2), one V(1), one Co(5), two equivalent Co(1), two equivalent Co(2), two equivalent Co(3), and two equivalent Co(4) atoms to form distorted CoLa2VCo9 cuboctahedra that share corners with four equivalent Co(4)La2VCo9 cuboctahedra, corners with four equivalent Co(2)La3Co9 cuboctahedra, corners with four equivalent Co(1)La3VCo8 cuboctahedra, corners with twelve equivalent Co(3)La2VCo9 cuboctahedra,  an edgeedge with one Co(3)La2VCo9 cuboctahedra,  an edgeedge with one Co(2)La3Co9 cuboctahedra,  an edgeedge with one Co(1)La3VCo8 cuboctahedra, edges with two equivalent Co(4)La2VCo9 cuboctahedra, faces with four equivalent Co(4)La2VCo9 cuboctahedra, faces with five equivalent Co(2)La3Co9 cuboctahedra, faces with five equivalent Co(1)La3VCo8 cuboctahedra, and faces with seven equivalent Co(3)La2VCo9 cuboctahedra. In the fourth Co site, Co(4) is bonded to one La(1), one La(2), one V(1), one Co(5), two equivalent Co(1), two equivalent Co(2), and four equivalent Co(3) atoms to form distorted CoLa2VCo9 cuboctahedra that share corners with four equivalent Co(4)La2VCo9 cuboctahedra, corners with five equivalent Co(2)La3Co9 cuboctahedra, corners with five equivalent Co(1)La3VCo8 cuboctahedra, corners with eight equivalent Co(3)La2VCo9 cuboctahedra, edges with three equivalent Co(2)La3Co9 cuboctahedra, edges with three equivalent Co(1)La3VCo8 cuboctahedra, edges with four equivalent Co(3)La2VCo9 cuboctahedra, faces with three equivalent Co(2)La3Co9 cuboctahedra, faces with three equivalent Co(1)La3VCo8 cuboctahedra, faces with four equivalent Co(4)La2VCo9 cuboctahedra, and faces with eight equivalent Co(3)La2VCo9 cuboctahedra. In the fifth Co site, Co(5) is bonded in a distorted single-bond geometry to one La(1), one V(1), three equivalent Co(2), three equivalent Co(4), and six equivalent Co(3) atoms.
La2VCo16 crystallizes in the trigonal R3m space group. There are two inequivalent La sites. In the first La site, La(1) is bonded in a 19-coordinate geometry to one Co(5), three equivalent Co(1), three equivalent Co(4), six equivalent Co(2), and six equivalent Co(3) atoms. The La(1)-Co(5) bond length is 3.06 Å. All La(1)-Co(1) bond lengths are 3.04 Å. All La(1)-Co(4) bond lengths are 3.26 Å. There are three shorter (3.11 Å) and three longer (3.22 Å) La(1)-Co(2) bond lengths. All La(1)-Co(3) bond lengths are 3.01 Å. In the second La site, La(2) is bonded in a 19-coordinate geometry to one V(1), three equivalent Co(2), three equivalent Co(4), six equivalent Co(1), and six equivalent Co(3) atoms. The La(2)-V(1) bond length is 3.14 Å. All La(2)-Co(2) bond lengths are 3.01 Å. All La(2)-Co(4) bond lengths are 3.30 Å. There are three shorter (3.15 Å) and three longer (3.18 Å) La(2)-Co(1) bond lengths. All La(2)-Co(3) bond lengths are 3.02 Å. V(1) is bonded in a 14-coordinate geometry to one La(2), one Co(5), three equivalent Co(1), three equivalent Co(4), and six equivalent Co(3) atoms. The V(1)-Co(5) bond length is 2.29 Å. All V(1)-Co(1) bond lengths are 2.59 Å. All V(1)-Co(4) bond lengths are 2.59 Å. All V(1)-Co(3) bond lengths are 2.67 Å. There are five inequivalent Co sites. In the first Co site, Co(1) is bonded to one La(1), two equivalent La(2), one V(1), two equivalent Co(2), two equivalent Co(4), and four equivalent Co(3) atoms to form CoLa3VCo8 cuboctahedra that share corners with two equivalent Co(1)La3VCo8 cuboctahedra, corners with five equivalent Co(4)La2VCo9 cuboctahedra, corners with eight equivalent Co(3)La2VCo9 cuboctahedra, corners with eight equivalent Co(2)La3Co9 cuboctahedra,  an edgeedge with one Co(2)La3Co9 cuboctahedra, edges with two equivalent Co(3)La2VCo9 cuboctahedra, edges with three equivalent Co(4)La2VCo9 cuboctahedra, edges with four equivalent Co(1)La3VCo8 cuboctahedra, faces with three equivalent Co(4)La2VCo9 cuboctahedra, faces with three equivalent Co(2)La3Co9 cuboctahedra, faces with four equivalent Co(1)La3VCo8 cuboctahedra, and faces with ten equivalent Co(3)La2VCo9 cuboctahedra. Both Co(1)-Co(2) bond lengths are 2.50 Å. Both Co(1)-Co(4) bond lengths are 2.40 Å. There are two shorter (2.52 Å) and two longer (2.60 Å) Co(1)-Co(3) bond lengths. In the second Co site, Co(2) is bonded to one La(2), two equivalent La(1), one Co(5), two equivalent Co(1), two equivalent Co(4), and four equivalent Co(3) atoms to form CoLa3Co9 cuboctahedra that share corners with two equivalent Co(2)La3Co9 cuboctahedra, corners with five equivalent Co(4)La2VCo9 cuboctahedra, corners with eight equivalent Co(3)La2VCo9 cuboctahedra, corners with eight equivalent Co(1)La3VCo8 cuboctahedra,  an edgeedge with one Co(1)La3VCo8 cuboctahedra, edges with two equivalent Co(3)La2VCo9 cuboctahedra, edges with three equivalent Co(4)La2VCo9 cuboctahedra, edges with four equivalent Co(2)La3Co9 cuboctahedra, faces with three equivalent Co(4)La2VCo9 cuboctahedra, faces with three equivalent Co(1)La3VCo8 cuboctahedra, faces with four equivalent Co(2)La3Co9 cuboctahedra, and faces with ten equivalent Co(3)La2VCo9 cuboctahedra. The Co(2)-Co(5) bond length is 2.58 Å. Both Co(2)-Co(4) bond lengths are 2.40 Å. There are two shorter (2.50 Å) and two longer (2.61 Å) Co(2)-Co(3) bond lengths. In the third Co site, Co(3) is bonded to one La(1), one La(2), one V(1), one Co(5), two equivalent Co(1), two equivalent Co(2), two equivalent Co(3), and two equivalent Co(4) atoms to form distorted CoLa2VCo9 cuboctahedra that share corners with four equivalent Co(4)La2VCo9 cuboctahedra, corners with four equivalent Co(2)La3Co9 cuboctahedra, corners with four equivalent Co(1)La3VCo8 cuboctahedra, corners with twelve equivalent Co(3)La2VCo9 cuboctahedra,  an edgeedge with one Co(3)La2VCo9 cuboctahedra,  an edgeedge with one Co(2)La3Co9 cuboctahedra,  an edgeedge with one Co(1)La3VCo8 cuboctahedra, edges with two equivalent Co(4)La2VCo9 cuboctahedra, faces with four equivalent Co(4)La2VCo9 cuboctahedra, faces with five equivalent Co(2)La3Co9 cuboctahedra, faces with five equivalent Co(1)La3VCo8 cuboctahedra, and faces with seven equivalent Co(3)La2VCo9 cuboctahedra. The Co(3)-Co(5) bond length is 2.67 Å. There is one shorter (2.40 Å) and one longer (2.41 Å) Co(3)-Co(3) bond length. There is one shorter (2.38 Å) and one longer (2.40 Å) Co(3)-Co(4) bond length. In the fourth Co site, Co(4) is bonded to one La(1), one La(2), one V(1), one Co(5), two equivalent Co(1), two equivalent Co(2), and four equivalent Co(3) atoms to form distorted CoLa2VCo9 cuboctahedra that share corners with four equivalent Co(4)La2VCo9 cuboctahedra, corners with five equivalent Co(2)La3Co9 cuboctahedra, corners with five equivalent Co(1)La3VCo8 cuboctahedra, corners with eight equivalent Co(3)La2VCo9 cuboctahedra, edges with three equivalent Co(2)La3Co9 cuboctahedra, edges with three equivalent Co(1)La3VCo8 cuboctahedra, edges with four equivalent Co(3)La2VCo9 cuboctahedra, faces with three equivalent Co(2)La3Co9 cuboctahedra, faces with three equivalent Co(1)La3VCo8 cuboctahedra, faces with four equivalent Co(4)La2VCo9 cuboctahedra, and faces with eight equivalent Co(3)La2VCo9 cuboctahedra. The Co(4)-Co(5) bond length is 2.58 Å. In the fifth Co site, Co(5) is bonded in a distorted single-bond geometry to one La(1), one V(1), three equivalent Co(2), three equivalent Co(4), and six equivalent Co(3) atoms.