YMg3 is beta Cu3Ti-like structured and crystallizes in the hexagonal P6_3/mmc space group. Mg(1) is bonded to eight equivalent Mg(1) and four equivalent Y(1) atoms to form distorted MgY4Mg8 cuboctahedra that share corners with four equivalent Y(1)Mg12 cuboctahedra, corners with fourteen equivalent Mg(1)Y4Mg8 cuboctahedra, edges with six equivalent Y(1)Mg12 cuboctahedra, edges with twelve equivalent Mg(1)Y4Mg8 cuboctahedra, faces with four equivalent Y(1)Mg12 cuboctahedra, and faces with sixteen equivalent Mg(1)Y4Mg8 cuboctahedra. Y(1) is bonded to twelve equivalent Mg(1) atoms to form YMg12 cuboctahedra that share corners with six equivalent Y(1)Mg12 cuboctahedra, corners with twelve equivalent Mg(1)Y4Mg8 cuboctahedra, edges with eighteen equivalent Mg(1)Y4Mg8 cuboctahedra, faces with eight equivalent Y(1)Mg12 cuboctahedra, and faces with twelve equivalent Mg(1)Y4Mg8 cuboctahedra.
YMg3 is beta Cu3Ti-like structured and crystallizes in the hexagonal P6_3/mmc space group. Mg(1) is bonded to eight equivalent Mg(1) and four equivalent Y(1) atoms to form distorted MgY4Mg8 cuboctahedra that share corners with four equivalent Y(1)Mg12 cuboctahedra, corners with fourteen equivalent Mg(1)Y4Mg8 cuboctahedra, edges with six equivalent Y(1)Mg12 cuboctahedra, edges with twelve equivalent Mg(1)Y4Mg8 cuboctahedra, faces with four equivalent Y(1)Mg12 cuboctahedra, and faces with sixteen equivalent Mg(1)Y4Mg8 cuboctahedra. There are a spread of Mg(1)-Mg(1) bond distances ranging from 3.20-3.42 Å. There are two shorter (3.25 Å) and two longer (3.34 Å) Mg(1)-Y(1) bond lengths. Y(1) is bonded to twelve equivalent Mg(1) atoms to form YMg12 cuboctahedra that share corners with six equivalent Y(1)Mg12 cuboctahedra, corners with twelve equivalent Mg(1)Y4Mg8 cuboctahedra, edges with eighteen equivalent Mg(1)Y4Mg8 cuboctahedra, faces with eight equivalent Y(1)Mg12 cuboctahedra, and faces with twelve equivalent Mg(1)Y4Mg8 cuboctahedra.