Mg3Hg is Uranium Silicide structured and crystallizes in the cubic Pm-3m space group. Mg(1) is bonded to eight equivalent Mg(1) and four equivalent Hg(1) atoms to form distorted MgMg8Hg4 cuboctahedra that share corners with twelve equivalent Mg(1)Mg8Hg4 cuboctahedra, edges with eight equivalent Hg(1)Mg12 cuboctahedra, edges with sixteen equivalent Mg(1)Mg8Hg4 cuboctahedra, faces with four equivalent Hg(1)Mg12 cuboctahedra, and faces with fourteen equivalent Mg(1)Mg8Hg4 cuboctahedra. Hg(1) is bonded to twelve equivalent Mg(1) atoms to form HgMg12 cuboctahedra that share corners with twelve equivalent Hg(1)Mg12 cuboctahedra, edges with twenty-four equivalent Mg(1)Mg8Hg4 cuboctahedra, faces with six equivalent Hg(1)Mg12 cuboctahedra, and faces with twelve equivalent Mg(1)Mg8Hg4 cuboctahedra.
Mg3Hg is Uranium Silicide structured and crystallizes in the cubic Pm-3m space group. Mg(1) is bonded to eight equivalent Mg(1) and four equivalent Hg(1) atoms to form distorted MgMg8Hg4 cuboctahedra that share corners with twelve equivalent Mg(1)Mg8Hg4 cuboctahedra, edges with eight equivalent Hg(1)Mg12 cuboctahedra, edges with sixteen equivalent Mg(1)Mg8Hg4 cuboctahedra, faces with four equivalent Hg(1)Mg12 cuboctahedra, and faces with fourteen equivalent Mg(1)Mg8Hg4 cuboctahedra. All Mg(1)-Mg(1) bond lengths are 3.08 Å. All Mg(1)-Hg(1) bond lengths are 3.08 Å. Hg(1) is bonded to twelve equivalent Mg(1) atoms to form HgMg12 cuboctahedra that share corners with twelve equivalent Hg(1)Mg12 cuboctahedra, edges with twenty-four equivalent Mg(1)Mg8Hg4 cuboctahedra, faces with six equivalent Hg(1)Mg12 cuboctahedra, and faces with twelve equivalent Mg(1)Mg8Hg4 cuboctahedra.