Mg5Y crystallizes in the monoclinic Cm space group. There are five inequivalent Mg sites. In the first Mg site, Mg(1) is bonded to one Mg(3), two equivalent Mg(1), two equivalent Mg(2), two equivalent Mg(4), three equivalent Mg(5), and two equivalent Y(1) atoms to form distorted MgY2Mg10 cuboctahedra that share corners with six equivalent Mg(1)Y2Mg10 cuboctahedra, corners with six equivalent Mg(2)Y3Mg9 cuboctahedra, corners with six equivalent Mg(4)YMg11 cuboctahedra, edges with two equivalent Mg(5)Y2Mg10 cuboctahedra, edges with three equivalent Mg(2)Y3Mg9 cuboctahedra, edges with three equivalent Mg(4)YMg11 cuboctahedra, edges with four equivalent Mg(3)Y2Mg10 cuboctahedra, edges with six equivalent Y(1)Y2Mg10 cuboctahedra, faces with two equivalent Mg(1)Y2Mg10 cuboctahedra, faces with three equivalent Mg(2)Y3Mg9 cuboctahedra, faces with three equivalent Mg(4)YMg11 cuboctahedra, faces with three equivalent Y(1)Y2Mg10 cuboctahedra, faces with four equivalent Mg(3)Y2Mg10 cuboctahedra, and faces with five equivalent Mg(5)Y2Mg10 cuboctahedra. In the second Mg site, Mg(2) is bonded to one Mg(5), two equivalent Mg(1), two equivalent Mg(2), two equivalent Mg(3), two equivalent Mg(4), and three equivalent Y(1) atoms to form MgY3Mg9 cuboctahedra that share corners with six equivalent Mg(1)Y2Mg10 cuboctahedra, corners with six equivalent Mg(2)Y3Mg9 cuboctahedra, corners with six equivalent Mg(4)YMg11 cuboctahedra, edges with two equivalent Y(1)Y2Mg10 cuboctahedra, edges with three equivalent Mg(1)Y2Mg10 cuboctahedra, edges with three equivalent Mg(4)YMg11 cuboctahedra, edges with four equivalent Mg(5)Y2Mg10 cuboctahedra, edges with six equivalent Mg(3)Y2Mg10 cuboctahedra, faces with two equivalent Mg(2)Y3Mg9 cuboctahedra, faces with three equivalent Mg(1)Y2Mg10 cuboctahedra, faces with three equivalent Mg(3)Y2Mg10 cuboctahedra, faces with three equivalent Mg(4)YMg11 cuboctahedra, faces with four equivalent Mg(5)Y2Mg10 cuboctahedra, and faces with five equivalent Y(1)Y2Mg10 cuboctahedra. In the third Mg site, Mg(3) is bonded to one Mg(1), two equivalent Mg(2), two equivalent Mg(3), two equivalent Mg(5), three equivalent Mg(4), and two equivalent Y(1) atoms to form MgY2Mg10 cuboctahedra that share corners with six equivalent Mg(3)Y2Mg10 cuboctahedra, corners with six equivalent Mg(5)Y2Mg10 cuboctahedra, corners with six equivalent Y(1)Y2Mg10 cuboctahedra, edges with two equivalent Mg(4)YMg11 cuboctahedra, edges with three equivalent Mg(5)Y2Mg10 cuboctahedra, edges with three equivalent Y(1)Y2Mg10 cuboctahedra, edges with four equivalent Mg(1)Y2Mg10 cuboctahedra, edges with six equivalent Mg(2)Y3Mg9 cuboctahedra, faces with two equivalent Mg(3)Y2Mg10 cuboctahedra, faces with three equivalent Mg(5)Y2Mg10 cuboctahedra, faces with three equivalent Mg(2)Y3Mg9 cuboctahedra, faces with three equivalent Y(1)Y2Mg10 cuboctahedra, faces with four equivalent Mg(1)Y2Mg10 cuboctahedra, and faces with five equivalent Mg(4)YMg11 cuboctahedra. In the fourth Mg site, Mg(4) is bonded to two equivalent Mg(1), two equivalent Mg(2), two equivalent Mg(4), two equivalent Mg(5), three equivalent Mg(3), and one Y(1) atom to form MgYMg11 cuboctahedra that share corners with six equivalent Mg(1)Y2Mg10 cuboctahedra, corners with six equivalent Mg(2)Y3Mg9 cuboctahedra, corners with six equivalent Mg(4)YMg11 cuboctahedra, edges with two equivalent Mg(3)Y2Mg10 cuboctahedra, edges with three equivalent Mg(1)Y2Mg10 cuboctahedra, edges with three equivalent Mg(2)Y3Mg9 cuboctahedra, edges with four equivalent Y(1)Y2Mg10 cuboctahedra, edges with six equivalent Mg(5)Y2Mg10 cuboctahedra, faces with two equivalent Mg(4)YMg11 cuboctahedra, faces with three equivalent Mg(1)Y2Mg10 cuboctahedra, faces with three equivalent Mg(5)Y2Mg10 cuboctahedra, faces with three equivalent Mg(2)Y3Mg9 cuboctahedra, faces with four equivalent Y(1)Y2Mg10 cuboctahedra, and faces with five equivalent Mg(3)Y2Mg10 cuboctahedra. In the fifth Mg site, Mg(5) is bonded to one Mg(2), two equivalent Mg(3), two equivalent Mg(4), two equivalent Mg(5), three equivalent Mg(1), and two equivalent Y(1) atoms to form distorted MgY2Mg10 cuboctahedra that share corners with six equivalent Mg(3)Y2Mg10 cuboctahedra, corners with six equivalent Mg(5)Y2Mg10 cuboctahedra, corners with six equivalent Y(1)Y2Mg10 cuboctahedra, edges with two equivalent Mg(1)Y2Mg10 cuboctahedra, edges with three equivalent Mg(3)Y2Mg10 cuboctahedra, edges with three equivalent Y(1)Y2Mg10 cuboctahedra, edges with four equivalent Mg(2)Y3Mg9 cuboctahedra, edges with six equivalent Mg(4)YMg11 cuboctahedra, faces with two equivalent Mg(5)Y2Mg10 cuboctahedra, faces with three equivalent Mg(3)Y2Mg10 cuboctahedra, faces with three equivalent Mg(4)YMg11 cuboctahedra, faces with three equivalent Y(1)Y2Mg10 cuboctahedra, faces with four equivalent Mg(2)Y3Mg9 cuboctahedra, and faces with five equivalent Mg(1)Y2Mg10 cuboctahedra. Y(1) is bonded to one Mg(4), two equivalent Mg(1), two equivalent Mg(3), two equivalent Mg(5), three equivalent Mg(2), and two equivalent Y(1) atoms to form YY2Mg10 cuboctahedra that share corners with six equivalent Mg(3)Y2Mg10 cuboctahedra, corners with six equivalent Mg(5)Y2Mg10 cuboctahedra, corners with six equivalent Y(1)Y2Mg10 cuboctahedra, edges with two equivalent Mg(2)Y3Mg9 cuboctahedra, edges with three equivalent Mg(3)Y2Mg10 cuboctahedra, edges with three equivalent Mg(5)Y2Mg10 cuboctahedra, edges with four equivalent Mg(4)YMg11 cuboctahedra, edges with six equivalent Mg(1)Y2Mg10 cuboctahedra, faces with two equivalent Y(1)Y2Mg10 cuboctahedra, faces with three equivalent Mg(1)Y2Mg10 cuboctahedra, faces with three equivalent Mg(3)Y2Mg10 cuboctahedra, faces with three equivalent Mg(5)Y2Mg10 cuboctahedra, faces with four equivalent Mg(4)YMg11 cuboctahedra, and faces with five equivalent Mg(2)Y3Mg9 cuboctahedra.
Mg5Y crystallizes in the monoclinic Cm space group. There are five inequivalent Mg sites. In the first Mg site, Mg(1) is bonded to one Mg(3), two equivalent Mg(1), two equivalent Mg(2), two equivalent Mg(4), three equivalent Mg(5), and two equivalent Y(1) atoms to form distorted MgY2Mg10 cuboctahedra that share corners with six equivalent Mg(1)Y2Mg10 cuboctahedra, corners with six equivalent Mg(2)Y3Mg9 cuboctahedra, corners with six equivalent Mg(4)YMg11 cuboctahedra, edges with two equivalent Mg(5)Y2Mg10 cuboctahedra, edges with three equivalent Mg(2)Y3Mg9 cuboctahedra, edges with three equivalent Mg(4)YMg11 cuboctahedra, edges with four equivalent Mg(3)Y2Mg10 cuboctahedra, edges with six equivalent Y(1)Y2Mg10 cuboctahedra, faces with two equivalent Mg(1)Y2Mg10 cuboctahedra, faces with three equivalent Mg(2)Y3Mg9 cuboctahedra, faces with three equivalent Mg(4)YMg11 cuboctahedra, faces with three equivalent Y(1)Y2Mg10 cuboctahedra, faces with four equivalent Mg(3)Y2Mg10 cuboctahedra, and faces with five equivalent Mg(5)Y2Mg10 cuboctahedra. The Mg(1)-Mg(3) bond length is 3.13 Å. Both Mg(1)-Mg(1) bond lengths are 3.24 Å. Both Mg(1)-Mg(2) bond lengths are 3.26 Å. Both Mg(1)-Mg(4) bond lengths are 3.28 Å. There are two shorter (3.26 Å) and one longer (3.49 Å) Mg(1)-Mg(5) bond length. Both Mg(1)-Y(1) bond lengths are 3.26 Å. In the second Mg site, Mg(2) is bonded to one Mg(5), two equivalent Mg(1), two equivalent Mg(2), two equivalent Mg(3), two equivalent Mg(4), and three equivalent Y(1) atoms to form MgY3Mg9 cuboctahedra that share corners with six equivalent Mg(1)Y2Mg10 cuboctahedra, corners with six equivalent Mg(2)Y3Mg9 cuboctahedra, corners with six equivalent Mg(4)YMg11 cuboctahedra, edges with two equivalent Y(1)Y2Mg10 cuboctahedra, edges with three equivalent Mg(1)Y2Mg10 cuboctahedra, edges with three equivalent Mg(4)YMg11 cuboctahedra, edges with four equivalent Mg(5)Y2Mg10 cuboctahedra, edges with six equivalent Mg(3)Y2Mg10 cuboctahedra, faces with two equivalent Mg(2)Y3Mg9 cuboctahedra, faces with three equivalent Mg(1)Y2Mg10 cuboctahedra, faces with three equivalent Mg(3)Y2Mg10 cuboctahedra, faces with three equivalent Mg(4)YMg11 cuboctahedra, faces with four equivalent Mg(5)Y2Mg10 cuboctahedra, and faces with five equivalent Y(1)Y2Mg10 cuboctahedra. The Mg(2)-Mg(5) bond length is 3.23 Å. Both Mg(2)-Mg(2) bond lengths are 3.24 Å. Both Mg(2)-Mg(3) bond lengths are 3.22 Å. Both Mg(2)-Mg(4) bond lengths are 3.31 Å. There are two shorter (3.36 Å) and one longer (3.38 Å) Mg(2)-Y(1) bond length. In the third Mg site, Mg(3) is bonded to one Mg(1), two equivalent Mg(2), two equivalent Mg(3), two equivalent Mg(5), three equivalent Mg(4), and two equivalent Y(1) atoms to form MgY2Mg10 cuboctahedra that share corners with six equivalent Mg(3)Y2Mg10 cuboctahedra, corners with six equivalent Mg(5)Y2Mg10 cuboctahedra, corners with six equivalent Y(1)Y2Mg10 cuboctahedra, edges with two equivalent Mg(4)YMg11 cuboctahedra, edges with three equivalent Mg(5)Y2Mg10 cuboctahedra, edges with three equivalent Y(1)Y2Mg10 cuboctahedra, edges with four equivalent Mg(1)Y2Mg10 cuboctahedra, edges with six equivalent Mg(2)Y3Mg9 cuboctahedra, faces with two equivalent Mg(3)Y2Mg10 cuboctahedra, faces with three equivalent Mg(5)Y2Mg10 cuboctahedra, faces with three equivalent Mg(2)Y3Mg9 cuboctahedra, faces with three equivalent Y(1)Y2Mg10 cuboctahedra, faces with four equivalent Mg(1)Y2Mg10 cuboctahedra, and faces with five equivalent Mg(4)YMg11 cuboctahedra. Both Mg(3)-Mg(3) bond lengths are 3.24 Å. Both Mg(3)-Mg(5) bond lengths are 3.19 Å. There is one shorter (3.36 Å) and two longer (3.37 Å) Mg(3)-Mg(4) bond lengths. Both Mg(3)-Y(1) bond lengths are 3.36 Å. In the fourth Mg site, Mg(4) is bonded to two equivalent Mg(1), two equivalent Mg(2), two equivalent Mg(4), two equivalent Mg(5), three equivalent Mg(3), and one Y(1) atom to form MgYMg11 cuboctahedra that share corners with six equivalent Mg(1)Y2Mg10 cuboctahedra, corners with six equivalent Mg(2)Y3Mg9 cuboctahedra, corners with six equivalent Mg(4)YMg11 cuboctahedra, edges with two equivalent Mg(3)Y2Mg10 cuboctahedra, edges with three equivalent Mg(1)Y2Mg10 cuboctahedra, edges with three equivalent Mg(2)Y3Mg9 cuboctahedra, edges with four equivalent Y(1)Y2Mg10 cuboctahedra, edges with six equivalent Mg(5)Y2Mg10 cuboctahedra, faces with two equivalent Mg(4)YMg11 cuboctahedra, faces with three equivalent Mg(1)Y2Mg10 cuboctahedra, faces with three equivalent Mg(5)Y2Mg10 cuboctahedra, faces with three equivalent Mg(2)Y3Mg9 cuboctahedra, faces with four equivalent Y(1)Y2Mg10 cuboctahedra, and faces with five equivalent Mg(3)Y2Mg10 cuboctahedra. Both Mg(4)-Mg(4) bond lengths are 3.24 Å. Both Mg(4)-Mg(5) bond lengths are 3.22 Å. The Mg(4)-Y(1) bond length is 3.25 Å. In the fifth Mg site, Mg(5) is bonded to one Mg(2), two equivalent Mg(3), two equivalent Mg(4), two equivalent Mg(5), three equivalent Mg(1), and two equivalent Y(1) atoms to form distorted MgY2Mg10 cuboctahedra that share corners with six equivalent Mg(3)Y2Mg10 cuboctahedra, corners with six equivalent Mg(5)Y2Mg10 cuboctahedra, corners with six equivalent Y(1)Y2Mg10 cuboctahedra, edges with two equivalent Mg(1)Y2Mg10 cuboctahedra, edges with three equivalent Mg(3)Y2Mg10 cuboctahedra, edges with three equivalent Y(1)Y2Mg10 cuboctahedra, edges with four equivalent Mg(2)Y3Mg9 cuboctahedra, edges with six equivalent Mg(4)YMg11 cuboctahedra, faces with two equivalent Mg(5)Y2Mg10 cuboctahedra, faces with three equivalent Mg(3)Y2Mg10 cuboctahedra, faces with three equivalent Mg(4)YMg11 cuboctahedra, faces with three equivalent Y(1)Y2Mg10 cuboctahedra, faces with four equivalent Mg(2)Y3Mg9 cuboctahedra, and faces with five equivalent Mg(1)Y2Mg10 cuboctahedra. Both Mg(5)-Mg(5) bond lengths are 3.24 Å. Both Mg(5)-Y(1) bond lengths are 3.30 Å. Y(1) is bonded to one Mg(4), two equivalent Mg(1), two equivalent Mg(3), two equivalent Mg(5), three equivalent Mg(2), and two equivalent Y(1) atoms to form YY2Mg10 cuboctahedra that share corners with six equivalent Mg(3)Y2Mg10 cuboctahedra, corners with six equivalent Mg(5)Y2Mg10 cuboctahedra, corners with six equivalent Y(1)Y2Mg10 cuboctahedra, edges with two equivalent Mg(2)Y3Mg9 cuboctahedra, edges with three equivalent Mg(3)Y2Mg10 cuboctahedra, edges with three equivalent Mg(5)Y2Mg10 cuboctahedra, edges with four equivalent Mg(4)YMg11 cuboctahedra, edges with six equivalent Mg(1)Y2Mg10 cuboctahedra, faces with two equivalent Y(1)Y2Mg10 cuboctahedra, faces with three equivalent Mg(1)Y2Mg10 cuboctahedra, faces with three equivalent Mg(3)Y2Mg10 cuboctahedra, faces with three equivalent Mg(5)Y2Mg10 cuboctahedra, faces with four equivalent Mg(4)YMg11 cuboctahedra, and faces with five equivalent Mg(2)Y3Mg9 cuboctahedra. Both Y(1)-Y(1) bond lengths are 3.24 Å.