Sm2(CoNi)5 crystallizes in the orthorhombic Pmmm space group. There are two inequivalent Sm sites. In the first Sm site, Sm(1) is bonded in a 18-coordinate geometry to two equivalent Co(1), four equivalent Co(2), four equivalent Ni(1), and eight equivalent Ni(2) atoms. In the second Sm site, Sm(2) is bonded in a 18-coordinate geometry to two equivalent Co(2), four equivalent Co(1), four equivalent Co(3), and eight equivalent Ni(2) atoms. There are three inequivalent Co sites. In the first Co site, Co(1) is bonded in a 9-coordinate geometry to one Sm(1), two equivalent Sm(2), two equivalent Co(3), and four equivalent Ni(2) atoms. In the second Co site, Co(2) is bonded in a 9-coordinate geometry to one Sm(2), two equivalent Sm(1), two equivalent Ni(1), and four equivalent Ni(2) atoms. In the third Co site, Co(3) is bonded to four equivalent Sm(2), four equivalent Co(1), and four equivalent Ni(2) atoms to form CoSm4Co4Ni4 cuboctahedra that share corners with four equivalent Co(3)Sm4Co4Ni4 cuboctahedra, corners with four equivalent Ni(1)Sm4Co4Ni4 cuboctahedra, corners with eight equivalent Ni(2)Sm4Co5Ni3 cuboctahedra, edges with two equivalent Co(3)Sm4Co4Ni4 cuboctahedra, edges with eight equivalent Ni(2)Sm4Co5Ni3 cuboctahedra, faces with two equivalent Co(3)Sm4Co4Ni4 cuboctahedra, and faces with eight equivalent Ni(2)Sm4Co5Ni3 cuboctahedra. There are two inequivalent Ni sites. In the first Ni site, Ni(1) is bonded to four equivalent Sm(1), four equivalent Co(2), and four equivalent Ni(2) atoms to form NiSm4Co4Ni4 cuboctahedra that share corners with four equivalent Co(3)Sm4Co4Ni4 cuboctahedra, corners with four equivalent Ni(1)Sm4Co4Ni4 cuboctahedra, corners with eight equivalent Ni(2)Sm4Co5Ni3 cuboctahedra, edges with two equivalent Ni(1)Sm4Co4Ni4 cuboctahedra, edges with eight equivalent Ni(2)Sm4Co5Ni3 cuboctahedra, faces with two equivalent Ni(1)Sm4Co4Ni4 cuboctahedra, and faces with eight equivalent Ni(2)Sm4Co5Ni3 cuboctahedra. In the second Ni site, Ni(2) is bonded to two equivalent Sm(1), two equivalent Sm(2), one Co(3), two equivalent Co(1), two equivalent Co(2), one Ni(1), and two equivalent Ni(2) atoms to form NiSm4Co5Ni3 cuboctahedra that share corners with two equivalent Co(3)Sm4Co4Ni4 cuboctahedra, corners with two equivalent Ni(1)Sm4Co4Ni4 cuboctahedra, corners with twelve equivalent Ni(2)Sm4Co5Ni3 cuboctahedra, edges with two equivalent Co(3)Sm4Co4Ni4 cuboctahedra, edges with two equivalent Ni(1)Sm4Co4Ni4 cuboctahedra, edges with six equivalent Ni(2)Sm4Co5Ni3 cuboctahedra, faces with two equivalent Co(3)Sm4Co4Ni4 cuboctahedra, faces with two equivalent Ni(1)Sm4Co4Ni4 cuboctahedra, and faces with six equivalent Ni(2)Sm4Co5Ni3 cuboctahedra.
Sm2(CoNi)5 crystallizes in the orthorhombic Pmmm space group. There are two inequivalent Sm sites. In the first Sm site, Sm(1) is bonded in a 18-coordinate geometry to two equivalent Co(1), four equivalent Co(2), four equivalent Ni(1), and eight equivalent Ni(2) atoms. Both Sm(1)-Co(1) bond lengths are 2.88 Å. All Sm(1)-Co(2) bond lengths are 2.85 Å. All Sm(1)-Ni(1) bond lengths are 3.17 Å. All Sm(1)-Ni(2) bond lengths are 3.17 Å. In the second Sm site, Sm(2) is bonded in a 18-coordinate geometry to two equivalent Co(2), four equivalent Co(1), four equivalent Co(3), and eight equivalent Ni(2) atoms. Both Sm(2)-Co(2) bond lengths are 2.84 Å. All Sm(2)-Co(1) bond lengths are 2.84 Å. All Sm(2)-Co(3) bond lengths are 3.17 Å. All Sm(2)-Ni(2) bond lengths are 3.16 Å. There are three inequivalent Co sites. In the first Co site, Co(1) is bonded in a 9-coordinate geometry to one Sm(1), two equivalent Sm(2), two equivalent Co(3), and four equivalent Ni(2) atoms. Both Co(1)-Co(3) bond lengths are 2.42 Å. All Co(1)-Ni(2) bond lengths are 2.45 Å. In the second Co site, Co(2) is bonded in a 9-coordinate geometry to one Sm(2), two equivalent Sm(1), two equivalent Ni(1), and four equivalent Ni(2) atoms. Both Co(2)-Ni(1) bond lengths are 2.44 Å. All Co(2)-Ni(2) bond lengths are 2.44 Å. In the third Co site, Co(3) is bonded to four equivalent Sm(2), four equivalent Co(1), and four equivalent Ni(2) atoms to form CoSm4Co4Ni4 cuboctahedra that share corners with four equivalent Co(3)Sm4Co4Ni4 cuboctahedra, corners with four equivalent Ni(1)Sm4Co4Ni4 cuboctahedra, corners with eight equivalent Ni(2)Sm4Co5Ni3 cuboctahedra, edges with two equivalent Co(3)Sm4Co4Ni4 cuboctahedra, edges with eight equivalent Ni(2)Sm4Co5Ni3 cuboctahedra, faces with two equivalent Co(3)Sm4Co4Ni4 cuboctahedra, and faces with eight equivalent Ni(2)Sm4Co5Ni3 cuboctahedra. All Co(3)-Ni(2) bond lengths are 2.47 Å. There are two inequivalent Ni sites. In the first Ni site, Ni(1) is bonded to four equivalent Sm(1), four equivalent Co(2), and four equivalent Ni(2) atoms to form NiSm4Co4Ni4 cuboctahedra that share corners with four equivalent Co(3)Sm4Co4Ni4 cuboctahedra, corners with four equivalent Ni(1)Sm4Co4Ni4 cuboctahedra, corners with eight equivalent Ni(2)Sm4Co5Ni3 cuboctahedra, edges with two equivalent Ni(1)Sm4Co4Ni4 cuboctahedra, edges with eight equivalent Ni(2)Sm4Co5Ni3 cuboctahedra, faces with two equivalent Ni(1)Sm4Co4Ni4 cuboctahedra, and faces with eight equivalent Ni(2)Sm4Co5Ni3 cuboctahedra. All Ni(1)-Ni(2) bond lengths are 2.47 Å. In the second Ni site, Ni(2) is bonded to two equivalent Sm(1), two equivalent Sm(2), one Co(3), two equivalent Co(1), two equivalent Co(2), one Ni(1), and two equivalent Ni(2) atoms to form NiSm4Co5Ni3 cuboctahedra that share corners with two equivalent Co(3)Sm4Co4Ni4 cuboctahedra, corners with two equivalent Ni(1)Sm4Co4Ni4 cuboctahedra, corners with twelve equivalent Ni(2)Sm4Co5Ni3 cuboctahedra, edges with two equivalent Co(3)Sm4Co4Ni4 cuboctahedra, edges with two equivalent Ni(1)Sm4Co4Ni4 cuboctahedra, edges with six equivalent Ni(2)Sm4Co5Ni3 cuboctahedra, faces with two equivalent Co(3)Sm4Co4Ni4 cuboctahedra, faces with two equivalent Ni(1)Sm4Co4Ni4 cuboctahedra, and faces with six equivalent Ni(2)Sm4Co5Ni3 cuboctahedra. There is one shorter (2.47 Å) and one longer (2.48 Å) Ni(2)-Ni(2) bond length.