MgSn3 crystallizes in the orthorhombic Pmm2 space group. Mg(1) is bonded to two equivalent Mg(1), two equivalent Sn(1), four equivalent Sn(2), and four equivalent Sn(3) atoms to form distorted MgMg2Sn10 cuboctahedra that share corners with ten equivalent Mg(1)Mg2Sn10 cuboctahedra, edges with two equivalent Mg(1)Mg2Sn10 cuboctahedra, edges with four equivalent Sn(1)Mg2Sn10 cuboctahedra, edges with eight equivalent Sn(2)Mg4Sn8 cuboctahedra, faces with four equivalent Mg(1)Mg2Sn10 cuboctahedra, faces with four equivalent Sn(2)Mg4Sn8 cuboctahedra, and faces with eight equivalent Sn(1)Mg2Sn10 cuboctahedra. There are three inequivalent Sn sites. In the first Sn site, Sn(1) is bonded to two equivalent Mg(1), two equivalent Sn(1), four equivalent Sn(2), and four equivalent Sn(3) atoms to form distorted SnMg2Sn10 cuboctahedra that share corners with eight equivalent Sn(2)Mg4Sn8 cuboctahedra, corners with ten equivalent Sn(1)Mg2Sn10 cuboctahedra, edges with two equivalent Sn(1)Mg2Sn10 cuboctahedra, edges with four equivalent Mg(1)Mg2Sn10 cuboctahedra, edges with four equivalent Sn(2)Mg4Sn8 cuboctahedra, faces with four equivalent Sn(1)Mg2Sn10 cuboctahedra, faces with four equivalent Sn(2)Mg4Sn8 cuboctahedra, and faces with eight equivalent Mg(1)Mg2Sn10 cuboctahedra. In the second Sn site, Sn(2) is bonded to four equivalent Mg(1), two equivalent Sn(2), two equivalent Sn(3), and four equivalent Sn(1) atoms to form distorted SnMg4Sn8 cuboctahedra that share corners with eight equivalent Sn(1)Mg2Sn10 cuboctahedra, corners with ten equivalent Sn(2)Mg4Sn8 cuboctahedra, edges with two equivalent Sn(2)Mg4Sn8 cuboctahedra, edges with four equivalent Sn(1)Mg2Sn10 cuboctahedra, edges with eight equivalent Mg(1)Mg2Sn10 cuboctahedra, faces with four equivalent Mg(1)Mg2Sn10 cuboctahedra, faces with four equivalent Sn(1)Mg2Sn10 cuboctahedra, and faces with four equivalent Sn(2)Mg4Sn8 cuboctahedra. In the third Sn site, Sn(3) is bonded in a 4-coordinate geometry to four equivalent Mg(1), two equivalent Sn(2), and four equivalent Sn(1) atoms.
MgSn3 crystallizes in the orthorhombic Pmm2 space group. Mg(1) is bonded to two equivalent Mg(1), two equivalent Sn(1), four equivalent Sn(2), and four equivalent Sn(3) atoms to form distorted MgMg2Sn10 cuboctahedra that share corners with ten equivalent Mg(1)Mg2Sn10 cuboctahedra, edges with two equivalent Mg(1)Mg2Sn10 cuboctahedra, edges with four equivalent Sn(1)Mg2Sn10 cuboctahedra, edges with eight equivalent Sn(2)Mg4Sn8 cuboctahedra, faces with four equivalent Mg(1)Mg2Sn10 cuboctahedra, faces with four equivalent Sn(2)Mg4Sn8 cuboctahedra, and faces with eight equivalent Sn(1)Mg2Sn10 cuboctahedra. Both Mg(1)-Mg(1) bond lengths are 3.34 Å. Both Mg(1)-Sn(1) bond lengths are 3.35 Å. All Mg(1)-Sn(2) bond lengths are 3.38 Å. There are two shorter (3.22 Å) and two longer (3.28 Å) Mg(1)-Sn(3) bond lengths. There are three inequivalent Sn sites. In the first Sn site, Sn(1) is bonded to two equivalent Mg(1), two equivalent Sn(1), four equivalent Sn(2), and four equivalent Sn(3) atoms to form distorted SnMg2Sn10 cuboctahedra that share corners with eight equivalent Sn(2)Mg4Sn8 cuboctahedra, corners with ten equivalent Sn(1)Mg2Sn10 cuboctahedra, edges with two equivalent Sn(1)Mg2Sn10 cuboctahedra, edges with four equivalent Mg(1)Mg2Sn10 cuboctahedra, edges with four equivalent Sn(2)Mg4Sn8 cuboctahedra, faces with four equivalent Sn(1)Mg2Sn10 cuboctahedra, faces with four equivalent Sn(2)Mg4Sn8 cuboctahedra, and faces with eight equivalent Mg(1)Mg2Sn10 cuboctahedra. Both Sn(1)-Sn(1) bond lengths are 3.34 Å. There are two shorter (3.20 Å) and two longer (3.31 Å) Sn(1)-Sn(2) bond lengths. All Sn(1)-Sn(3) bond lengths are 3.41 Å. In the second Sn site, Sn(2) is bonded to four equivalent Mg(1), two equivalent Sn(2), two equivalent Sn(3), and four equivalent Sn(1) atoms to form distorted SnMg4Sn8 cuboctahedra that share corners with eight equivalent Sn(1)Mg2Sn10 cuboctahedra, corners with ten equivalent Sn(2)Mg4Sn8 cuboctahedra, edges with two equivalent Sn(2)Mg4Sn8 cuboctahedra, edges with four equivalent Sn(1)Mg2Sn10 cuboctahedra, edges with eight equivalent Mg(1)Mg2Sn10 cuboctahedra, faces with four equivalent Mg(1)Mg2Sn10 cuboctahedra, faces with four equivalent Sn(1)Mg2Sn10 cuboctahedra, and faces with four equivalent Sn(2)Mg4Sn8 cuboctahedra. Both Sn(2)-Sn(2) bond lengths are 3.34 Å. Both Sn(2)-Sn(3) bond lengths are 3.37 Å. In the third Sn site, Sn(3) is bonded in a 4-coordinate geometry to four equivalent Mg(1), two equivalent Sn(2), and four equivalent Sn(1) atoms.