Mg5Ag crystallizes in the trigonal R32 space group. There are two inequivalent Mg sites. In the first Mg site, Mg(1) is bonded in a distorted bent 150 degrees geometry to four equivalent Mg(2) and two equivalent Ag(1) atoms. In the second Mg site, Mg(2) is bonded to three equivalent Mg(2), six equivalent Mg(1), and three equivalent Ag(1) atoms to form distorted MgMg9Ag3 cuboctahedra that share corners with six equivalent Ag(1)Mg12 cuboctahedra, corners with twelve equivalent Mg(2)Mg9Ag3 cuboctahedra, edges with six equivalent Mg(2)Mg9Ag3 cuboctahedra, faces with four equivalent Mg(2)Mg9Ag3 cuboctahedra, and faces with four equivalent Ag(1)Mg12 cuboctahedra. Ag(1) is bonded to six equivalent Mg(1) and six equivalent Mg(2) atoms to form AgMg12 cuboctahedra that share corners with six equivalent Ag(1)Mg12 cuboctahedra, corners with twelve equivalent Mg(2)Mg9Ag3 cuboctahedra, edges with six equivalent Ag(1)Mg12 cuboctahedra, and faces with eight equivalent Mg(2)Mg9Ag3 cuboctahedra.
Mg5Ag crystallizes in the trigonal R32 space group. There are two inequivalent Mg sites. In the first Mg site, Mg(1) is bonded in a distorted bent 150 degrees geometry to four equivalent Mg(2) and two equivalent Ag(1) atoms. There are two shorter (3.06 Å) and two longer (3.07 Å) Mg(1)-Mg(2) bond lengths. Both Mg(1)-Ag(1) bond lengths are 3.04 Å. In the second Mg site, Mg(2) is bonded to three equivalent Mg(2), six equivalent Mg(1), and three equivalent Ag(1) atoms to form distorted MgMg9Ag3 cuboctahedra that share corners with six equivalent Ag(1)Mg12 cuboctahedra, corners with twelve equivalent Mg(2)Mg9Ag3 cuboctahedra, edges with six equivalent Mg(2)Mg9Ag3 cuboctahedra, faces with four equivalent Mg(2)Mg9Ag3 cuboctahedra, and faces with four equivalent Ag(1)Mg12 cuboctahedra. All Mg(2)-Mg(2) bond lengths are 3.10 Å. All Mg(2)-Ag(1) bond lengths are 3.10 Å. Ag(1) is bonded to six equivalent Mg(1) and six equivalent Mg(2) atoms to form AgMg12 cuboctahedra that share corners with six equivalent Ag(1)Mg12 cuboctahedra, corners with twelve equivalent Mg(2)Mg9Ag3 cuboctahedra, edges with six equivalent Ag(1)Mg12 cuboctahedra, and faces with eight equivalent Mg(2)Mg9Ag3 cuboctahedra.