Mg6YMo crystallizes in the orthorhombic Amm2 space group. There are four inequivalent Mg sites. In the first Mg site, Mg(1) is bonded to two equivalent Mg(1), two equivalent Mg(2), two equivalent Mg(3), two equivalent Mg(4), two equivalent Y(1), and two equivalent Mo(1) atoms to form distorted MgY2Mg8Mo2 cuboctahedra that share corners with four equivalent Y(1)Mg10Mo2 cuboctahedra, corners with four equivalent Mo(1)Y2Mg10 cuboctahedra, corners with ten equivalent Mg(1)Y2Mg8Mo2 cuboctahedra, edges with two equivalent Mg(1)Y2Mg8Mo2 cuboctahedra, edges with two equivalent Y(1)Mg10Mo2 cuboctahedra, edges with two equivalent Mo(1)Y2Mg10 cuboctahedra, edges with four equivalent Mg(3)Y2Mg10 cuboctahedra, faces with two equivalent Mg(3)Y2Mg10 cuboctahedra, faces with two equivalent Y(1)Mg10Mo2 cuboctahedra, faces with two equivalent Mo(1)Y2Mg10 cuboctahedra, and faces with four equivalent Mg(1)Y2Mg8Mo2 cuboctahedra. In the second Mg site, Mg(2) is bonded in a 2-coordinate geometry to two equivalent Mg(1), two equivalent Mg(3), two equivalent Y(1), and two equivalent Mo(1) atoms. In the third Mg site, Mg(3) is bonded to two equivalent Mg(4), four equivalent Mg(1), four equivalent Mg(2), and two equivalent Y(1) atoms to form distorted MgY2Mg10 cuboctahedra that share corners with six equivalent Mg(3)Y2Mg10 cuboctahedra, edges with four equivalent Y(1)Mg10Mo2 cuboctahedra, edges with eight equivalent Mg(1)Y2Mg8Mo2 cuboctahedra, faces with two equivalent Mg(3)Y2Mg10 cuboctahedra, faces with two equivalent Y(1)Mg10Mo2 cuboctahedra, faces with four equivalent Mg(1)Y2Mg8Mo2 cuboctahedra, and faces with six equivalent Mo(1)Y2Mg10 cuboctahedra. In the fourth Mg site, Mg(4) is bonded in a distorted bent 120 degrees geometry to two equivalent Mg(3), four equivalent Mg(1), and two equivalent Mo(1) atoms. Y(1) is bonded to two equivalent Mg(3), four equivalent Mg(1), four equivalent Mg(2), and two equivalent Mo(1) atoms to form distorted YMg10Mo2 cuboctahedra that share corners with four equivalent Mo(1)Y2Mg10 cuboctahedra, corners with six equivalent Y(1)Mg10Mo2 cuboctahedra, corners with eight equivalent Mg(1)Y2Mg8Mo2 cuboctahedra, edges with two equivalent Mo(1)Y2Mg10 cuboctahedra, edges with four equivalent Mg(3)Y2Mg10 cuboctahedra, edges with four equivalent Mg(1)Y2Mg8Mo2 cuboctahedra, faces with two equivalent Mg(3)Y2Mg10 cuboctahedra, faces with two equivalent Y(1)Mg10Mo2 cuboctahedra, faces with two equivalent Mo(1)Y2Mg10 cuboctahedra, and faces with four equivalent Mg(1)Y2Mg8Mo2 cuboctahedra. Mo(1) is bonded to two equivalent Mg(4), four equivalent Mg(1), four equivalent Mg(2), and two equivalent Y(1) atoms to form MoY2Mg10 cuboctahedra that share corners with four equivalent Y(1)Mg10Mo2 cuboctahedra, corners with six equivalent Mo(1)Y2Mg10 cuboctahedra, corners with eight equivalent Mg(1)Y2Mg8Mo2 cuboctahedra, edges with two equivalent Y(1)Mg10Mo2 cuboctahedra, edges with four equivalent Mg(1)Y2Mg8Mo2 cuboctahedra, faces with two equivalent Y(1)Mg10Mo2 cuboctahedra, faces with two equivalent Mo(1)Y2Mg10 cuboctahedra, faces with four equivalent Mg(1)Y2Mg8Mo2 cuboctahedra, and faces with six equivalent Mg(3)Y2Mg10 cuboctahedra.
Mg6YMo crystallizes in the orthorhombic Amm2 space group. There are four inequivalent Mg sites. In the first Mg site, Mg(1) is bonded to two equivalent Mg(1), two equivalent Mg(2), two equivalent Mg(3), two equivalent Mg(4), two equivalent Y(1), and two equivalent Mo(1) atoms to form distorted MgY2Mg8Mo2 cuboctahedra that share corners with four equivalent Y(1)Mg10Mo2 cuboctahedra, corners with four equivalent Mo(1)Y2Mg10 cuboctahedra, corners with ten equivalent Mg(1)Y2Mg8Mo2 cuboctahedra, edges with two equivalent Mg(1)Y2Mg8Mo2 cuboctahedra, edges with two equivalent Y(1)Mg10Mo2 cuboctahedra, edges with two equivalent Mo(1)Y2Mg10 cuboctahedra, edges with four equivalent Mg(3)Y2Mg10 cuboctahedra, faces with two equivalent Mg(3)Y2Mg10 cuboctahedra, faces with two equivalent Y(1)Mg10Mo2 cuboctahedra, faces with two equivalent Mo(1)Y2Mg10 cuboctahedra, and faces with four equivalent Mg(1)Y2Mg8Mo2 cuboctahedra. There is one shorter (3.02 Å) and one longer (3.04 Å) Mg(1)-Mg(1) bond length. Both Mg(1)-Mg(2) bond lengths are 3.12 Å. Both Mg(1)-Mg(3) bond lengths are 3.13 Å. Both Mg(1)-Mg(4) bond lengths are 3.24 Å. There is one shorter (3.27 Å) and one longer (3.29 Å) Mg(1)-Y(1) bond length. There is one shorter (3.18 Å) and one longer (3.38 Å) Mg(1)-Mo(1) bond length. In the second Mg site, Mg(2) is bonded in a 2-coordinate geometry to two equivalent Mg(1), two equivalent Mg(3), two equivalent Y(1), and two equivalent Mo(1) atoms. There is one shorter (3.18 Å) and one longer (3.37 Å) Mg(2)-Mg(3) bond length. Both Mg(2)-Y(1) bond lengths are 3.19 Å. Both Mg(2)-Mo(1) bond lengths are 3.07 Å. In the third Mg site, Mg(3) is bonded to two equivalent Mg(4), four equivalent Mg(1), four equivalent Mg(2), and two equivalent Y(1) atoms to form distorted MgY2Mg10 cuboctahedra that share corners with six equivalent Mg(3)Y2Mg10 cuboctahedra, edges with four equivalent Y(1)Mg10Mo2 cuboctahedra, edges with eight equivalent Mg(1)Y2Mg8Mo2 cuboctahedra, faces with two equivalent Mg(3)Y2Mg10 cuboctahedra, faces with two equivalent Y(1)Mg10Mo2 cuboctahedra, faces with four equivalent Mg(1)Y2Mg8Mo2 cuboctahedra, and faces with six equivalent Mo(1)Y2Mg10 cuboctahedra. Both Mg(3)-Mg(4) bond lengths are 3.05 Å. Both Mg(3)-Y(1) bond lengths are 3.15 Å. In the fourth Mg site, Mg(4) is bonded in a distorted bent 120 degrees geometry to two equivalent Mg(3), four equivalent Mg(1), and two equivalent Mo(1) atoms. Both Mg(4)-Mo(1) bond lengths are 3.04 Å. Y(1) is bonded to two equivalent Mg(3), four equivalent Mg(1), four equivalent Mg(2), and two equivalent Mo(1) atoms to form distorted YMg10Mo2 cuboctahedra that share corners with four equivalent Mo(1)Y2Mg10 cuboctahedra, corners with six equivalent Y(1)Mg10Mo2 cuboctahedra, corners with eight equivalent Mg(1)Y2Mg8Mo2 cuboctahedra, edges with two equivalent Mo(1)Y2Mg10 cuboctahedra, edges with four equivalent Mg(3)Y2Mg10 cuboctahedra, edges with four equivalent Mg(1)Y2Mg8Mo2 cuboctahedra, faces with two equivalent Mg(3)Y2Mg10 cuboctahedra, faces with two equivalent Y(1)Mg10Mo2 cuboctahedra, faces with two equivalent Mo(1)Y2Mg10 cuboctahedra, and faces with four equivalent Mg(1)Y2Mg8Mo2 cuboctahedra. Both Y(1)-Mo(1) bond lengths are 3.03 Å. Mo(1) is bonded to two equivalent Mg(4), four equivalent Mg(1), four equivalent Mg(2), and two equivalent Y(1) atoms to form MoY2Mg10 cuboctahedra that share corners with four equivalent Y(1)Mg10Mo2 cuboctahedra, corners with six equivalent Mo(1)Y2Mg10 cuboctahedra, corners with eight equivalent Mg(1)Y2Mg8Mo2 cuboctahedra, edges with two equivalent Y(1)Mg10Mo2 cuboctahedra, edges with four equivalent Mg(1)Y2Mg8Mo2 cuboctahedra, faces with two equivalent Y(1)Mg10Mo2 cuboctahedra, faces with two equivalent Mo(1)Y2Mg10 cuboctahedra, faces with four equivalent Mg(1)Y2Mg8Mo2 cuboctahedra, and faces with six equivalent Mg(3)Y2Mg10 cuboctahedra.