MgSm5 crystallizes in the orthorhombic Amm2 space group. Mg(1) is bonded in a 10-coordinate geometry to two equivalent Sm(3), two equivalent Sm(4), two equivalent Sm(5), and four equivalent Sm(2) atoms. There are five inequivalent Sm sites. In the first Sm site, Sm(1) is bonded to two equivalent Sm(1), two equivalent Sm(2), two equivalent Sm(3), two equivalent Sm(5), and four equivalent Sm(4) atoms to form SmSm12 cuboctahedra that share corners with six equivalent Sm(3)Sm10Mg2 cuboctahedra, corners with six equivalent Sm(1)Sm12 cuboctahedra, corners with six equivalent Sm(2)Sm8Mg4 cuboctahedra, edges with three equivalent Sm(3)Sm10Mg2 cuboctahedra, edges with three equivalent Sm(2)Sm8Mg4 cuboctahedra, edges with four equivalent Sm(4)Sm10Mg2 cuboctahedra, faces with two equivalent Sm(3)Sm10Mg2 cuboctahedra, faces with two equivalent Sm(2)Sm8Mg4 cuboctahedra, faces with four equivalent Sm(4)Sm10Mg2 cuboctahedra, faces with four equivalent Sm(1)Sm12 cuboctahedra, and faces with six equivalent Sm(5)Sm10Mg2 cuboctahedra. In the second Sm site, Sm(2) is bonded to four equivalent Mg(1), two equivalent Sm(1), two equivalent Sm(2), two equivalent Sm(3), and two equivalent Sm(4) atoms to form SmSm8Mg4 cuboctahedra that share corners with six equivalent Sm(3)Sm10Mg2 cuboctahedra, corners with six equivalent Sm(1)Sm12 cuboctahedra, corners with six equivalent Sm(2)Sm8Mg4 cuboctahedra, edges with three equivalent Sm(3)Sm10Mg2 cuboctahedra, edges with three equivalent Sm(1)Sm12 cuboctahedra, edges with eight equivalent Sm(5)Sm10Mg2 cuboctahedra, faces with two equivalent Sm(3)Sm10Mg2 cuboctahedra, faces with two equivalent Sm(5)Sm10Mg2 cuboctahedra, faces with two equivalent Sm(1)Sm12 cuboctahedra, faces with four equivalent Sm(2)Sm8Mg4 cuboctahedra, and faces with six equivalent Sm(4)Sm10Mg2 cuboctahedra. In the third Sm site, Sm(3) is bonded to two equivalent Mg(1), two equivalent Sm(1), two equivalent Sm(2), two equivalent Sm(3), and four equivalent Sm(5) atoms to form SmSm10Mg2 cuboctahedra that share corners with six equivalent Sm(3)Sm10Mg2 cuboctahedra, corners with six equivalent Sm(1)Sm12 cuboctahedra, corners with six equivalent Sm(2)Sm8Mg4 cuboctahedra, edges with three equivalent Sm(1)Sm12 cuboctahedra, edges with three equivalent Sm(2)Sm8Mg4 cuboctahedra, edges with four equivalent Sm(5)Sm10Mg2 cuboctahedra, edges with eight equivalent Sm(4)Sm10Mg2 cuboctahedra, faces with two equivalent Sm(4)Sm10Mg2 cuboctahedra, faces with two equivalent Sm(1)Sm12 cuboctahedra, faces with two equivalent Sm(2)Sm8Mg4 cuboctahedra, faces with four equivalent Sm(3)Sm10Mg2 cuboctahedra, and faces with four equivalent Sm(5)Sm10Mg2 cuboctahedra. In the fourth Sm site, Sm(4) is bonded to two equivalent Mg(1), two equivalent Sm(2), two equivalent Sm(4), two equivalent Sm(5), and four equivalent Sm(1) atoms to form SmSm10Mg2 cuboctahedra that share corners with six equivalent Sm(4)Sm10Mg2 cuboctahedra, corners with six equivalent Sm(5)Sm10Mg2 cuboctahedra, edges with three equivalent Sm(5)Sm10Mg2 cuboctahedra, edges with four equivalent Sm(1)Sm12 cuboctahedra, edges with eight equivalent Sm(3)Sm10Mg2 cuboctahedra, faces with two equivalent Sm(3)Sm10Mg2 cuboctahedra, faces with two equivalent Sm(5)Sm10Mg2 cuboctahedra, faces with four equivalent Sm(4)Sm10Mg2 cuboctahedra, faces with four equivalent Sm(1)Sm12 cuboctahedra, and faces with six equivalent Sm(2)Sm8Mg4 cuboctahedra. In the fifth Sm site, Sm(5) is bonded to two equivalent Mg(1), two equivalent Sm(1), two equivalent Sm(4), two equivalent Sm(5), and four equivalent Sm(3) atoms to form distorted SmSm10Mg2 cuboctahedra that share corners with six equivalent Sm(4)Sm10Mg2 cuboctahedra, corners with six equivalent Sm(5)Sm10Mg2 cuboctahedra, edges with three equivalent Sm(4)Sm10Mg2 cuboctahedra, edges with four equivalent Sm(3)Sm10Mg2 cuboctahedra, edges with eight equivalent Sm(2)Sm8Mg4 cuboctahedra, faces with two equivalent Sm(4)Sm10Mg2 cuboctahedra, faces with two equivalent Sm(2)Sm8Mg4 cuboctahedra, faces with four equivalent Sm(3)Sm10Mg2 cuboctahedra, faces with four equivalent Sm(5)Sm10Mg2 cuboctahedra, and faces with six equivalent Sm(1)Sm12 cuboctahedra.
MgSm5 crystallizes in the orthorhombic Amm2 space group. Mg(1) is bonded in a 10-coordinate geometry to two equivalent Sm(3), two equivalent Sm(4), two equivalent Sm(5), and four equivalent Sm(2) atoms. Both Mg(1)-Sm(3) bond lengths are 3.53 Å. Both Mg(1)-Sm(4) bond lengths are 3.54 Å. Both Mg(1)-Sm(5) bond lengths are 3.47 Å. All Mg(1)-Sm(2) bond lengths are 3.52 Å. There are five inequivalent Sm sites. In the first Sm site, Sm(1) is bonded to two equivalent Sm(1), two equivalent Sm(2), two equivalent Sm(3), two equivalent Sm(5), and four equivalent Sm(4) atoms to form SmSm12 cuboctahedra that share corners with six equivalent Sm(3)Sm10Mg2 cuboctahedra, corners with six equivalent Sm(1)Sm12 cuboctahedra, corners with six equivalent Sm(2)Sm8Mg4 cuboctahedra, edges with three equivalent Sm(3)Sm10Mg2 cuboctahedra, edges with three equivalent Sm(2)Sm8Mg4 cuboctahedra, edges with four equivalent Sm(4)Sm10Mg2 cuboctahedra, faces with two equivalent Sm(3)Sm10Mg2 cuboctahedra, faces with two equivalent Sm(2)Sm8Mg4 cuboctahedra, faces with four equivalent Sm(4)Sm10Mg2 cuboctahedra, faces with four equivalent Sm(1)Sm12 cuboctahedra, and faces with six equivalent Sm(5)Sm10Mg2 cuboctahedra. Both Sm(1)-Sm(1) bond lengths are 3.65 Å. Both Sm(1)-Sm(2) bond lengths are 3.59 Å. Both Sm(1)-Sm(3) bond lengths are 3.62 Å. Both Sm(1)-Sm(5) bond lengths are 3.64 Å. All Sm(1)-Sm(4) bond lengths are 3.54 Å. In the second Sm site, Sm(2) is bonded to four equivalent Mg(1), two equivalent Sm(1), two equivalent Sm(2), two equivalent Sm(3), and two equivalent Sm(4) atoms to form SmSm8Mg4 cuboctahedra that share corners with six equivalent Sm(3)Sm10Mg2 cuboctahedra, corners with six equivalent Sm(1)Sm12 cuboctahedra, corners with six equivalent Sm(2)Sm8Mg4 cuboctahedra, edges with three equivalent Sm(3)Sm10Mg2 cuboctahedra, edges with three equivalent Sm(1)Sm12 cuboctahedra, edges with eight equivalent Sm(5)Sm10Mg2 cuboctahedra, faces with two equivalent Sm(3)Sm10Mg2 cuboctahedra, faces with two equivalent Sm(5)Sm10Mg2 cuboctahedra, faces with two equivalent Sm(1)Sm12 cuboctahedra, faces with four equivalent Sm(2)Sm8Mg4 cuboctahedra, and faces with six equivalent Sm(4)Sm10Mg2 cuboctahedra. Both Sm(2)-Sm(2) bond lengths are 3.65 Å. Both Sm(2)-Sm(3) bond lengths are 3.45 Å. Both Sm(2)-Sm(4) bond lengths are 3.60 Å. In the third Sm site, Sm(3) is bonded to two equivalent Mg(1), two equivalent Sm(1), two equivalent Sm(2), two equivalent Sm(3), and four equivalent Sm(5) atoms to form SmSm10Mg2 cuboctahedra that share corners with six equivalent Sm(3)Sm10Mg2 cuboctahedra, corners with six equivalent Sm(1)Sm12 cuboctahedra, corners with six equivalent Sm(2)Sm8Mg4 cuboctahedra, edges with three equivalent Sm(1)Sm12 cuboctahedra, edges with three equivalent Sm(2)Sm8Mg4 cuboctahedra, edges with four equivalent Sm(5)Sm10Mg2 cuboctahedra, edges with eight equivalent Sm(4)Sm10Mg2 cuboctahedra, faces with two equivalent Sm(4)Sm10Mg2 cuboctahedra, faces with two equivalent Sm(1)Sm12 cuboctahedra, faces with two equivalent Sm(2)Sm8Mg4 cuboctahedra, faces with four equivalent Sm(3)Sm10Mg2 cuboctahedra, and faces with four equivalent Sm(5)Sm10Mg2 cuboctahedra. Both Sm(3)-Sm(3) bond lengths are 3.65 Å. All Sm(3)-Sm(5) bond lengths are 3.52 Å. In the fourth Sm site, Sm(4) is bonded to two equivalent Mg(1), two equivalent Sm(2), two equivalent Sm(4), two equivalent Sm(5), and four equivalent Sm(1) atoms to form SmSm10Mg2 cuboctahedra that share corners with six equivalent Sm(4)Sm10Mg2 cuboctahedra, corners with six equivalent Sm(5)Sm10Mg2 cuboctahedra, edges with three equivalent Sm(5)Sm10Mg2 cuboctahedra, edges with four equivalent Sm(1)Sm12 cuboctahedra, edges with eight equivalent Sm(3)Sm10Mg2 cuboctahedra, faces with two equivalent Sm(3)Sm10Mg2 cuboctahedra, faces with two equivalent Sm(5)Sm10Mg2 cuboctahedra, faces with four equivalent Sm(4)Sm10Mg2 cuboctahedra, faces with four equivalent Sm(1)Sm12 cuboctahedra, and faces with six equivalent Sm(2)Sm8Mg4 cuboctahedra. Both Sm(4)-Sm(4) bond lengths are 3.65 Å. Both Sm(4)-Sm(5) bond lengths are 3.65 Å. In the fifth Sm site, Sm(5) is bonded to two equivalent Mg(1), two equivalent Sm(1), two equivalent Sm(4), two equivalent Sm(5), and four equivalent Sm(3) atoms to form distorted SmSm10Mg2 cuboctahedra that share corners with six equivalent Sm(4)Sm10Mg2 cuboctahedra, corners with six equivalent Sm(5)Sm10Mg2 cuboctahedra, edges with three equivalent Sm(4)Sm10Mg2 cuboctahedra, edges with four equivalent Sm(3)Sm10Mg2 cuboctahedra, edges with eight equivalent Sm(2)Sm8Mg4 cuboctahedra, faces with two equivalent Sm(4)Sm10Mg2 cuboctahedra, faces with two equivalent Sm(2)Sm8Mg4 cuboctahedra, faces with four equivalent Sm(3)Sm10Mg2 cuboctahedra, faces with four equivalent Sm(5)Sm10Mg2 cuboctahedra, and faces with six equivalent Sm(1)Sm12 cuboctahedra. Both Sm(5)-Sm(5) bond lengths are 3.65 Å.