SmNiGa3 crystallizes in the tetragonal I-4m2 space group. Sm(1) is bonded in a 16-coordinate geometry to four equivalent Ni(1), four equivalent Ga(2), and eight equivalent Ga(1) atoms. Ni(1) is bonded to four equivalent Sm(1), four equivalent Ga(1), and four equivalent Ga(2) atoms to form distorted NiSm4Ga8 cuboctahedra that share corners with four equivalent Ga(2)Sm4Ga4Ni4 cuboctahedra, corners with twelve equivalent Ni(1)Sm4Ga8 cuboctahedra, edges with two equivalent Ga(2)Sm4Ga4Ni4 cuboctahedra, faces with four equivalent Ni(1)Sm4Ga8 cuboctahedra, and faces with four equivalent Ga(2)Sm4Ga4Ni4 cuboctahedra. There are two inequivalent Ga sites. In the first Ga site, Ga(1) is bonded in a 9-coordinate geometry to four equivalent Sm(1), two equivalent Ni(1), one Ga(1), and two equivalent Ga(2) atoms. In the second Ga site, Ga(2) is bonded to four equivalent Sm(1), four equivalent Ni(1), and four equivalent Ga(1) atoms to form GaSm4Ga4Ni4 cuboctahedra that share corners with four equivalent Ni(1)Sm4Ga8 cuboctahedra, corners with twelve equivalent Ga(2)Sm4Ga4Ni4 cuboctahedra, edges with two equivalent Ni(1)Sm4Ga8 cuboctahedra, faces with four equivalent Ni(1)Sm4Ga8 cuboctahedra, and faces with four equivalent Ga(2)Sm4Ga4Ni4 cuboctahedra.
SmNiGa3 crystallizes in the tetragonal I-4m2 space group. Sm(1) is bonded in a 16-coordinate geometry to four equivalent Ni(1), four equivalent Ga(2), and eight equivalent Ga(1) atoms. All Sm(1)-Ni(1) bond lengths are 3.35 Å. All Sm(1)-Ga(2) bond lengths are 3.35 Å. All Sm(1)-Ga(1) bond lengths are 3.15 Å. Ni(1) is bonded to four equivalent Sm(1), four equivalent Ga(1), and four equivalent Ga(2) atoms to form distorted NiSm4Ga8 cuboctahedra that share corners with four equivalent Ga(2)Sm4Ga4Ni4 cuboctahedra, corners with twelve equivalent Ni(1)Sm4Ga8 cuboctahedra, edges with two equivalent Ga(2)Sm4Ga4Ni4 cuboctahedra, faces with four equivalent Ni(1)Sm4Ga8 cuboctahedra, and faces with four equivalent Ga(2)Sm4Ga4Ni4 cuboctahedra. All Ni(1)-Ga(1) bond lengths are 2.49 Å. All Ni(1)-Ga(2) bond lengths are 2.90 Å. There are two inequivalent Ga sites. In the first Ga site, Ga(1) is bonded in a 9-coordinate geometry to four equivalent Sm(1), two equivalent Ni(1), one Ga(1), and two equivalent Ga(2) atoms. The Ga(1)-Ga(1) bond length is 2.49 Å. Both Ga(1)-Ga(2) bond lengths are 2.49 Å. In the second Ga site, Ga(2) is bonded to four equivalent Sm(1), four equivalent Ni(1), and four equivalent Ga(1) atoms to form GaSm4Ga4Ni4 cuboctahedra that share corners with four equivalent Ni(1)Sm4Ga8 cuboctahedra, corners with twelve equivalent Ga(2)Sm4Ga4Ni4 cuboctahedra, edges with two equivalent Ni(1)Sm4Ga8 cuboctahedra, faces with four equivalent Ni(1)Sm4Ga8 cuboctahedra, and faces with four equivalent Ga(2)Sm4Ga4Ni4 cuboctahedra.