MgY3 is alpha La-derived structured and crystallizes in the tetragonal I4/mmm space group. Mg(1) is bonded to four equivalent Y(1) and eight equivalent Y(2) atoms to form MgY12 cuboctahedra that share corners with four equivalent Mg(1)Y12 cuboctahedra, corners with eight equivalent Y(1)Y8Mg4 cuboctahedra, edges with eight equivalent Mg(1)Y12 cuboctahedra, edges with sixteen equivalent Y(2)Y8Mg4 cuboctahedra, faces with four equivalent Mg(1)Y12 cuboctahedra, faces with six equivalent Y(1)Y8Mg4 cuboctahedra, and faces with eight equivalent Y(2)Y8Mg4 cuboctahedra. There are two inequivalent Y sites. In the first Y site, Y(1) is bonded to four equivalent Mg(1) and eight equivalent Y(2) atoms to form YY8Mg4 cuboctahedra that share corners with four equivalent Y(1)Y8Mg4 cuboctahedra, corners with eight equivalent Mg(1)Y12 cuboctahedra, edges with eight equivalent Y(1)Y8Mg4 cuboctahedra, edges with sixteen equivalent Y(2)Y8Mg4 cuboctahedra, faces with four equivalent Y(1)Y8Mg4 cuboctahedra, faces with six equivalent Mg(1)Y12 cuboctahedra, and faces with eight equivalent Y(2)Y8Mg4 cuboctahedra. In the second Y site, Y(2) is bonded to four equivalent Mg(1), four equivalent Y(1), and four equivalent Y(2) atoms to form YY8Mg4 cuboctahedra that share corners with twelve equivalent Y(2)Y8Mg4 cuboctahedra, edges with eight equivalent Mg(1)Y12 cuboctahedra, edges with eight equivalent Y(1)Y8Mg4 cuboctahedra, edges with eight equivalent Y(2)Y8Mg4 cuboctahedra, faces with four equivalent Mg(1)Y12 cuboctahedra, faces with four equivalent Y(1)Y8Mg4 cuboctahedra, and faces with ten equivalent Y(2)Y8Mg4 cuboctahedra.
MgY3 is alpha La-derived structured and crystallizes in the tetragonal I4/mmm space group. Mg(1) is bonded to four equivalent Y(1) and eight equivalent Y(2) atoms to form MgY12 cuboctahedra that share corners with four equivalent Mg(1)Y12 cuboctahedra, corners with eight equivalent Y(1)Y8Mg4 cuboctahedra, edges with eight equivalent Mg(1)Y12 cuboctahedra, edges with sixteen equivalent Y(2)Y8Mg4 cuboctahedra, faces with four equivalent Mg(1)Y12 cuboctahedra, faces with six equivalent Y(1)Y8Mg4 cuboctahedra, and faces with eight equivalent Y(2)Y8Mg4 cuboctahedra. All Mg(1)-Y(1) bond lengths are 3.50 Å. All Mg(1)-Y(2) bond lengths are 3.48 Å. There are two inequivalent Y sites. In the first Y site, Y(1) is bonded to four equivalent Mg(1) and eight equivalent Y(2) atoms to form YY8Mg4 cuboctahedra that share corners with four equivalent Y(1)Y8Mg4 cuboctahedra, corners with eight equivalent Mg(1)Y12 cuboctahedra, edges with eight equivalent Y(1)Y8Mg4 cuboctahedra, edges with sixteen equivalent Y(2)Y8Mg4 cuboctahedra, faces with four equivalent Y(1)Y8Mg4 cuboctahedra, faces with six equivalent Mg(1)Y12 cuboctahedra, and faces with eight equivalent Y(2)Y8Mg4 cuboctahedra. All Y(1)-Y(2) bond lengths are 3.48 Å. In the second Y site, Y(2) is bonded to four equivalent Mg(1), four equivalent Y(1), and four equivalent Y(2) atoms to form YY8Mg4 cuboctahedra that share corners with twelve equivalent Y(2)Y8Mg4 cuboctahedra, edges with eight equivalent Mg(1)Y12 cuboctahedra, edges with eight equivalent Y(1)Y8Mg4 cuboctahedra, edges with eight equivalent Y(2)Y8Mg4 cuboctahedra, faces with four equivalent Mg(1)Y12 cuboctahedra, faces with four equivalent Y(1)Y8Mg4 cuboctahedra, and faces with ten equivalent Y(2)Y8Mg4 cuboctahedra. All Y(2)-Y(2) bond lengths are 3.50 Å.