SmPtGa3 crystallizes in the tetragonal I-4m2 space group. Sm(1) is bonded in a 16-coordinate geometry to four equivalent Pt(1), four equivalent Ga(2), and eight equivalent Ga(1) atoms. Pt(1) is bonded to four equivalent Sm(1), four equivalent Ga(1), and four equivalent Ga(2) atoms to form distorted PtSm4Ga8 cuboctahedra that share corners with four equivalent Ga(2)Sm4Ga4Pt4 cuboctahedra, corners with twelve equivalent Pt(1)Sm4Ga8 cuboctahedra, edges with two equivalent Ga(2)Sm4Ga4Pt4 cuboctahedra, faces with four equivalent Pt(1)Sm4Ga8 cuboctahedra, and faces with four equivalent Ga(2)Sm4Ga4Pt4 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 Pt(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 Pt(1), and four equivalent Ga(1) atoms to form GaSm4Ga4Pt4 cuboctahedra that share corners with four equivalent Pt(1)Sm4Ga8 cuboctahedra, corners with twelve equivalent Ga(2)Sm4Ga4Pt4 cuboctahedra, edges with two equivalent Pt(1)Sm4Ga8 cuboctahedra, faces with four equivalent Pt(1)Sm4Ga8 cuboctahedra, and faces with four equivalent Ga(2)Sm4Ga4Pt4 cuboctahedra.
SmPtGa3 crystallizes in the tetragonal I-4m2 space group. Sm(1) is bonded in a 16-coordinate geometry to four equivalent Pt(1), four equivalent Ga(2), and eight equivalent Ga(1) atoms. All Sm(1)-Pt(1) bond lengths are 3.40 Å. All Sm(1)-Ga(2) bond lengths are 3.40 Å. All Sm(1)-Ga(1) bond lengths are 3.17 Å. Pt(1) is bonded to four equivalent Sm(1), four equivalent Ga(1), and four equivalent Ga(2) atoms to form distorted PtSm4Ga8 cuboctahedra that share corners with four equivalent Ga(2)Sm4Ga4Pt4 cuboctahedra, corners with twelve equivalent Pt(1)Sm4Ga8 cuboctahedra, edges with two equivalent Ga(2)Sm4Ga4Pt4 cuboctahedra, faces with four equivalent Pt(1)Sm4Ga8 cuboctahedra, and faces with four equivalent Ga(2)Sm4Ga4Pt4 cuboctahedra. All Pt(1)-Ga(1) bond lengths are 2.54 Å. All Pt(1)-Ga(2) bond lengths are 2.93 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 Pt(1), one Ga(1), and two equivalent Ga(2) atoms. The Ga(1)-Ga(1) bond length is 2.44 Å. Both Ga(1)-Ga(2) bond lengths are 2.54 Å. In the second Ga site, Ga(2) is bonded to four equivalent Sm(1), four equivalent Pt(1), and four equivalent Ga(1) atoms to form GaSm4Ga4Pt4 cuboctahedra that share corners with four equivalent Pt(1)Sm4Ga8 cuboctahedra, corners with twelve equivalent Ga(2)Sm4Ga4Pt4 cuboctahedra, edges with two equivalent Pt(1)Sm4Ga8 cuboctahedra, faces with four equivalent Pt(1)Sm4Ga8 cuboctahedra, and faces with four equivalent Ga(2)Sm4Ga4Pt4 cuboctahedra.