Mg5Sn crystallizes in the trigonal R32 space group. There are seven inequivalent Mg sites. In the first Mg site, Mg(1) is bonded to four equivalent Mg(2), six equivalent Mg(1), and two equivalent Sn(1) atoms to form distorted MgMg10Sn2 cuboctahedra that share corners with eighteen Mg(1,1,1,1)Mg10Sn2 cuboctahedra; edges with four equivalent Sn(1)Mg12 cuboctahedra; edges with six equivalent Mg(1)Mg10Sn2 cuboctahedra; edges with eight equivalent Mg(2)Mg9Sn3 cuboctahedra; faces with four equivalent Sn(1)Mg12 cuboctahedra; faces with eight Mg(1,1)Mg10Sn2 cuboctahedra; and faces with eight equivalent Mg(2)Mg9Sn3 cuboctahedra. In the second Mg site, Mg(2) is bonded to three equivalent Mg(2); six Mg(1,1,1,1); and three equivalent Sn(1) atoms to form distorted MgMg9Sn3 cuboctahedra that share corners with six equivalent Sn(1)Mg12 cuboctahedra; corners with twelve Mg(2,2)Mg9Sn3 cuboctahedra; edges with six equivalent Mg(2)Mg9Sn3 cuboctahedra; edges with twelve Mg(1,1,1,1)Mg10Sn2 cuboctahedra; faces with four equivalent Mg(2)Mg9Sn3 cuboctahedra; faces with four equivalent Sn(1)Mg12 cuboctahedra; and faces with twelve Mg(1,1,1,1)Mg10Sn2 cuboctahedra. In the third Mg site, Mg(1) is bonded to four equivalent Mg(2); six Mg(1,1); and two equivalent Sn(1) atoms to form distorted MgMg10Sn2 cuboctahedra that share corners with eighteen Mg(1,1,1)Mg10Sn2 cuboctahedra; edges with four equivalent Sn(1)Mg12 cuboctahedra; edges with six equivalent Mg(1)Mg10Sn2 cuboctahedra; edges with eight equivalent Mg(2)Mg9Sn3 cuboctahedra; faces with four equivalent Sn(1)Mg12 cuboctahedra; faces with eight Mg(1,1,1,1)Mg10Sn2 cuboctahedra; and faces with eight equivalent Mg(2)Mg9Sn3 cuboctahedra. In the fourth Mg site, Mg(1) is bonded to four Mg(2,2); six Mg(1,1); and two equivalent Sn(1) atoms to form distorted MgMg10Sn2 cuboctahedra that share corners with eighteen Mg(1,1,1)Mg10Sn2 cuboctahedra; edges with four equivalent Sn(1)Mg12 cuboctahedra; edges with six equivalent Mg(1)Mg10Sn2 cuboctahedra; edges with eight Mg(2,2)Mg9Sn3 cuboctahedra; faces with four equivalent Sn(1)Mg12 cuboctahedra; faces with eight Mg(1,1,1)Mg10Sn2 cuboctahedra; and faces with eight Mg(2,2)Mg9Sn3 cuboctahedra. In the fifth Mg site, Mg(1) is bonded to four Mg(2,2); six Mg(1,1); and two equivalent Sn(1) atoms to form distorted MgMg10Sn2 cuboctahedra that share corners with eighteen Mg(1,1,1,1)Mg10Sn2 cuboctahedra; edges with four equivalent Sn(1)Mg12 cuboctahedra; edges with six equivalent Mg(1)Mg10Sn2 cuboctahedra; edges with eight Mg(2,2)Mg9Sn3 cuboctahedra; faces with four equivalent Sn(1)Mg12 cuboctahedra; faces with eight Mg(1,1,1)Mg10Sn2 cuboctahedra; and faces with eight Mg(2,2)Mg9Sn3 cuboctahedra. In the sixth Mg site, Mg(1) is bonded to four Mg(2,2); six Mg(1,1); and two equivalent Sn(1) atoms to form distorted MgMg10Sn2 cuboctahedra that share corners with eighteen Mg(1,1,1)Mg10Sn2 cuboctahedra; edges with four equivalent Sn(1)Mg12 cuboctahedra; edges with six equivalent Mg(1)Mg10Sn2 cuboctahedra; edges with eight Mg(2,2)Mg9Sn3 cuboctahedra; faces with four equivalent Sn(1)Mg12 cuboctahedra; faces with eight Mg(1,1,1)Mg10Sn2 cuboctahedra; and faces with eight Mg(2,2)Mg9Sn3 cuboctahedra. In the seventh Mg site, Mg(2) is bonded to three equivalent Mg(2); six Mg(1,1,1,1); and three equivalent Sn(1) atoms to form distorted MgMg9Sn3 cuboctahedra that share corners with six equivalent Sn(1)Mg12 cuboctahedra; corners with twelve equivalent Mg(2)Mg9Sn3 cuboctahedra; edges with six equivalent Mg(2)Mg9Sn3 cuboctahedra; edges with twelve Mg(1,1,1,1)Mg10Sn2 cuboctahedra; faces with four equivalent Mg(2)Mg9Sn3 cuboctahedra; faces with four equivalent Sn(1)Mg12 cuboctahedra; and faces with twelve Mg(1,1,1,1)Mg10Sn2 cuboctahedra. Sn(1) is bonded to six Mg(1,1,1,1) and six equivalent Mg(2) atoms to form SnMg12 cuboctahedra that share corners with six equivalent Sn(1)Mg12 cuboctahedra; corners with twelve equivalent Mg(2)Mg9Sn3 cuboctahedra; edges with six equivalent Sn(1)Mg12 cuboctahedra; edges with twelve Mg(1,1,1,1)Mg10Sn2 cuboctahedra; faces with eight Mg(2,2)Mg9Sn3 cuboctahedra; and faces with twelve Mg(1,1,1,1)Mg10Sn2 cuboctahedra.
Mg5Sn crystallizes in the trigonal R32 space group. There are seven inequivalent Mg sites. In the first Mg site, Mg(1) is bonded to four equivalent Mg(2), six equivalent Mg(1), and two equivalent Sn(1) atoms to form distorted MgMg10Sn2 cuboctahedra that share corners with eighteen Mg(1,1,1,1)Mg10Sn2 cuboctahedra; edges with four equivalent Sn(1)Mg12 cuboctahedra; edges with six equivalent Mg(1)Mg10Sn2 cuboctahedra; edges with eight equivalent Mg(2)Mg9Sn3 cuboctahedra; faces with four equivalent Sn(1)Mg12 cuboctahedra; faces with eight Mg(1,1)Mg10Sn2 cuboctahedra; and faces with eight equivalent Mg(2)Mg9Sn3 cuboctahedra. There are two shorter (3.17 Å) and two longer (3.18 Å) Mg(1)-Mg(2) bond lengths. There are four shorter (3.17 Å) and two longer (3.19 Å) Mg(1)-Mg(1) bond lengths. Both Mg(1)-Sn(1) bond lengths are 3.17 Å. In the second Mg site, Mg(2) is bonded to three equivalent Mg(2); six Mg(1,1,1,1); and three equivalent Sn(1) atoms to form distorted MgMg9Sn3 cuboctahedra that share corners with six equivalent Sn(1)Mg12 cuboctahedra; corners with twelve Mg(2,2)Mg9Sn3 cuboctahedra; edges with six equivalent Mg(2)Mg9Sn3 cuboctahedra; edges with twelve Mg(1,1,1,1)Mg10Sn2 cuboctahedra; faces with four equivalent Mg(2)Mg9Sn3 cuboctahedra; faces with four equivalent Sn(1)Mg12 cuboctahedra; and faces with twelve Mg(1,1,1,1)Mg10Sn2 cuboctahedra. All Mg(2)-Mg(2) bond lengths are 3.18 Å. There are three shorter (3.17 Å) and two longer (3.18 Å) Mg(2)-Mg(1,1,1) bond lengths. All Mg(2)-Sn(1) bond lengths are 3.18 Å. In the third Mg site, Mg(1) is bonded to four equivalent Mg(2); six Mg(1,1); and two equivalent Sn(1) atoms to form distorted MgMg10Sn2 cuboctahedra that share corners with eighteen Mg(1,1,1)Mg10Sn2 cuboctahedra; edges with four equivalent Sn(1)Mg12 cuboctahedra; edges with six equivalent Mg(1)Mg10Sn2 cuboctahedra; edges with eight equivalent Mg(2)Mg9Sn3 cuboctahedra; faces with four equivalent Sn(1)Mg12 cuboctahedra; faces with eight Mg(1,1,1,1)Mg10Sn2 cuboctahedra; and faces with eight equivalent Mg(2)Mg9Sn3 cuboctahedra. There are two shorter (3.17 Å) and one longer (3.19 Å) Mg(1)-Mg(1) bond length. Both Mg(1)-Sn(1) bond lengths are 3.17 Å. In the fourth Mg site, Mg(1) is bonded to four Mg(2,2); six Mg(1,1); and two equivalent Sn(1) atoms to form distorted MgMg10Sn2 cuboctahedra that share corners with eighteen Mg(1,1,1)Mg10Sn2 cuboctahedra; edges with four equivalent Sn(1)Mg12 cuboctahedra; edges with six equivalent Mg(1)Mg10Sn2 cuboctahedra; edges with eight Mg(2,2)Mg9Sn3 cuboctahedra; faces with four equivalent Sn(1)Mg12 cuboctahedra; faces with eight Mg(1,1,1)Mg10Sn2 cuboctahedra; and faces with eight Mg(2,2)Mg9Sn3 cuboctahedra. There are two shorter (3.17 Å) and two longer (3.18 Å) Mg(1)-Mg(2,2) bond lengths. There are four shorter (3.17 Å) and two longer (3.19 Å) Mg(1)-Mg(1,1) bond lengths. Both Mg(1)-Sn(1) bond lengths are 3.17 Å. In the fifth Mg site, Mg(1) is bonded to four Mg(2,2); six Mg(1,1); and two equivalent Sn(1) atoms to form distorted MgMg10Sn2 cuboctahedra that share corners with eighteen Mg(1,1,1,1)Mg10Sn2 cuboctahedra; edges with four equivalent Sn(1)Mg12 cuboctahedra; edges with six equivalent Mg(1)Mg10Sn2 cuboctahedra; edges with eight Mg(2,2)Mg9Sn3 cuboctahedra; faces with four equivalent Sn(1)Mg12 cuboctahedra; faces with eight Mg(1,1,1)Mg10Sn2 cuboctahedra; and faces with eight Mg(2,2)Mg9Sn3 cuboctahedra. The Mg(1)-Mg(2) bond length is 3.18 Å. There are two shorter (3.17 Å) and one longer (3.19 Å) Mg(1)-Mg(1) bond length. Both Mg(1)-Sn(1) bond lengths are 3.17 Å. In the sixth Mg site, Mg(1) is bonded to four Mg(2,2); six Mg(1,1); and two equivalent Sn(1) atoms to form distorted MgMg10Sn2 cuboctahedra that share corners with eighteen Mg(1,1,1)Mg10Sn2 cuboctahedra; edges with four equivalent Sn(1)Mg12 cuboctahedra; edges with six equivalent Mg(1)Mg10Sn2 cuboctahedra; edges with eight Mg(2,2)Mg9Sn3 cuboctahedra; faces with four equivalent Sn(1)Mg12 cuboctahedra; faces with eight Mg(1,1,1)Mg10Sn2 cuboctahedra; and faces with eight Mg(2,2)Mg9Sn3 cuboctahedra. The Mg(1)-Mg(2) bond length is 3.17 Å. There are four shorter (3.17 Å) and two longer (3.19 Å) Mg(1)-Mg(1,1) bond lengths. Both Mg(1)-Sn(1) bond lengths are 3.17 Å. In the seventh Mg site, Mg(2) is bonded to three equivalent Mg(2); six Mg(1,1,1,1); and three equivalent Sn(1) atoms to form distorted MgMg9Sn3 cuboctahedra that share corners with six equivalent Sn(1)Mg12 cuboctahedra; corners with twelve equivalent Mg(2)Mg9Sn3 cuboctahedra; edges with six equivalent Mg(2)Mg9Sn3 cuboctahedra; edges with twelve Mg(1,1,1,1)Mg10Sn2 cuboctahedra; faces with four equivalent Mg(2)Mg9Sn3 cuboctahedra; faces with four equivalent Sn(1)Mg12 cuboctahedra; and faces with twelve Mg(1,1,1,1)Mg10Sn2 cuboctahedra. All Mg(2)-Mg(2) bond lengths are 3.18 Å. There is one shorter (3.17 Å) and one longer (3.18 Å) Mg(2)-Mg(1) bond length. All Mg(2)-Sn(1) bond lengths are 3.18 Å. Sn(1) is bonded to six Mg(1,1,1,1) and six equivalent Mg(2) atoms to form SnMg12 cuboctahedra that share corners with six equivalent Sn(1)Mg12 cuboctahedra; corners with twelve equivalent Mg(2)Mg9Sn3 cuboctahedra; edges with six equivalent Sn(1)Mg12 cuboctahedra; edges with twelve Mg(1,1,1,1)Mg10Sn2 cuboctahedra; faces with eight Mg(2,2)Mg9Sn3 cuboctahedra; and faces with twelve Mg(1,1,1,1)Mg10Sn2 cuboctahedra.