MgY5 crystallizes in the monoclinic Cm space group. Mg(1) is bonded in a 10-coordinate geometry to one Y(4), two equivalent Y(1), two equivalent Y(3), two equivalent Y(5), and three equivalent Y(2) atoms. There are five inequivalent Y sites. In the first Y site, Y(1) is bonded to two equivalent Mg(1), one Y(3), two equivalent Y(1), two equivalent Y(2), two equivalent Y(4), and three equivalent Y(5) atoms to form distorted YY10Mg2 cuboctahedra that share corners with six equivalent Y(1)Y10Mg2 cuboctahedra, corners with six equivalent Y(4)Y11Mg cuboctahedra, corners with six equivalent Y(2)Y9Mg3 cuboctahedra, edges with two equivalent Y(5)Y10Mg2 cuboctahedra, edges with three equivalent Y(4)Y11Mg cuboctahedra, edges with three equivalent Y(2)Y9Mg3 cuboctahedra, edges with four equivalent Y(3)Y10Mg2 cuboctahedra, faces with two equivalent Y(1)Y10Mg2 cuboctahedra, faces with three equivalent Y(4)Y11Mg cuboctahedra, faces with three equivalent Y(2)Y9Mg3 cuboctahedra, faces with four equivalent Y(3)Y10Mg2 cuboctahedra, and faces with five equivalent Y(5)Y10Mg2 cuboctahedra. In the second Y site, Y(2) is bonded to three equivalent Mg(1), one Y(5), two equivalent Y(1), two equivalent Y(2), two equivalent Y(3), and two equivalent Y(4) atoms to form YY9Mg3 cuboctahedra that share corners with six equivalent Y(1)Y10Mg2 cuboctahedra, corners with six equivalent Y(4)Y11Mg cuboctahedra, corners with six equivalent Y(2)Y9Mg3 cuboctahedra, edges with three equivalent Y(1)Y10Mg2 cuboctahedra, edges with three equivalent Y(4)Y11Mg cuboctahedra, edges with four equivalent Y(5)Y10Mg2 cuboctahedra, edges with six equivalent Y(3)Y10Mg2 cuboctahedra, faces with two equivalent Y(2)Y9Mg3 cuboctahedra, faces with three equivalent Y(1)Y10Mg2 cuboctahedra, faces with three equivalent Y(3)Y10Mg2 cuboctahedra, faces with three equivalent Y(4)Y11Mg cuboctahedra, and faces with four equivalent Y(5)Y10Mg2 cuboctahedra. In the third Y site, Y(3) is bonded to two equivalent Mg(1), one Y(1), two equivalent Y(2), two equivalent Y(3), two equivalent Y(5), and three equivalent Y(4) atoms to form distorted YY10Mg2 cuboctahedra that share corners with six equivalent Y(3)Y10Mg2 cuboctahedra, corners with six equivalent Y(5)Y10Mg2 cuboctahedra, edges with two equivalent Y(4)Y11Mg cuboctahedra, edges with three equivalent Y(5)Y10Mg2 cuboctahedra, edges with four equivalent Y(1)Y10Mg2 cuboctahedra, edges with six equivalent Y(2)Y9Mg3 cuboctahedra, faces with two equivalent Y(3)Y10Mg2 cuboctahedra, faces with three equivalent Y(5)Y10Mg2 cuboctahedra, faces with three equivalent Y(2)Y9Mg3 cuboctahedra, faces with four equivalent Y(1)Y10Mg2 cuboctahedra, and faces with five equivalent Y(4)Y11Mg cuboctahedra. In the fourth Y site, Y(4) is bonded to one Mg(1), two equivalent Y(1), two equivalent Y(2), two equivalent Y(4), two equivalent Y(5), and three equivalent Y(3) atoms to form YY11Mg cuboctahedra that share corners with six equivalent Y(1)Y10Mg2 cuboctahedra, corners with six equivalent Y(4)Y11Mg cuboctahedra, corners with six equivalent Y(2)Y9Mg3 cuboctahedra, edges with two equivalent Y(3)Y10Mg2 cuboctahedra, edges with three equivalent Y(1)Y10Mg2 cuboctahedra, edges with three equivalent Y(2)Y9Mg3 cuboctahedra, edges with six equivalent Y(5)Y10Mg2 cuboctahedra, faces with two equivalent Y(4)Y11Mg cuboctahedra, faces with three equivalent Y(1)Y10Mg2 cuboctahedra, faces with three equivalent Y(5)Y10Mg2 cuboctahedra, faces with three equivalent Y(2)Y9Mg3 cuboctahedra, and faces with five equivalent Y(3)Y10Mg2 cuboctahedra. In the fifth Y site, Y(5) is bonded to two equivalent Mg(1), one Y(2), two equivalent Y(3), two equivalent Y(4), two equivalent Y(5), and three equivalent Y(1) atoms to form YY10Mg2 cuboctahedra that share corners with six equivalent Y(3)Y10Mg2 cuboctahedra, corners with six equivalent Y(5)Y10Mg2 cuboctahedra, edges with two equivalent Y(1)Y10Mg2 cuboctahedra, edges with three equivalent Y(3)Y10Mg2 cuboctahedra, edges with four equivalent Y(2)Y9Mg3 cuboctahedra, edges with six equivalent Y(4)Y11Mg cuboctahedra, faces with two equivalent Y(5)Y10Mg2 cuboctahedra, faces with three equivalent Y(3)Y10Mg2 cuboctahedra, faces with three equivalent Y(4)Y11Mg cuboctahedra, faces with four equivalent Y(2)Y9Mg3 cuboctahedra, and faces with five equivalent Y(1)Y10Mg2 cuboctahedra.
MgY5 crystallizes in the monoclinic Cm space group. Mg(1) is bonded in a 10-coordinate geometry to one Y(4), two equivalent Y(1), two equivalent Y(3), two equivalent Y(5), and three equivalent Y(2) atoms. The Mg(1)-Y(4) bond length is 3.61 Å. Both Mg(1)-Y(1) bond lengths are 3.45 Å. Both Mg(1)-Y(3) bond lengths are 3.41 Å. Both Mg(1)-Y(5) bond lengths are 3.58 Å. There are two shorter (3.42 Å) and one longer (3.67 Å) Mg(1)-Y(2) bond length. There are five inequivalent Y sites. In the first Y site, Y(1) is bonded to two equivalent Mg(1), one Y(3), two equivalent Y(1), two equivalent Y(2), two equivalent Y(4), and three equivalent Y(5) atoms to form distorted YY10Mg2 cuboctahedra that share corners with six equivalent Y(1)Y10Mg2 cuboctahedra, corners with six equivalent Y(4)Y11Mg cuboctahedra, corners with six equivalent Y(2)Y9Mg3 cuboctahedra, edges with two equivalent Y(5)Y10Mg2 cuboctahedra, edges with three equivalent Y(4)Y11Mg cuboctahedra, edges with three equivalent Y(2)Y9Mg3 cuboctahedra, edges with four equivalent Y(3)Y10Mg2 cuboctahedra, faces with two equivalent Y(1)Y10Mg2 cuboctahedra, faces with three equivalent Y(4)Y11Mg cuboctahedra, faces with three equivalent Y(2)Y9Mg3 cuboctahedra, faces with four equivalent Y(3)Y10Mg2 cuboctahedra, and faces with five equivalent Y(5)Y10Mg2 cuboctahedra. The Y(1)-Y(3) bond length is 3.71 Å. Both Y(1)-Y(1) bond lengths are 3.63 Å. Both Y(1)-Y(2) bond lengths are 3.56 Å. Both Y(1)-Y(4) bond lengths are 3.59 Å. There is one shorter (3.52 Å) and two longer (3.57 Å) Y(1)-Y(5) bond lengths. In the second Y site, Y(2) is bonded to three equivalent Mg(1), one Y(5), two equivalent Y(1), two equivalent Y(2), two equivalent Y(3), and two equivalent Y(4) atoms to form YY9Mg3 cuboctahedra that share corners with six equivalent Y(1)Y10Mg2 cuboctahedra, corners with six equivalent Y(4)Y11Mg cuboctahedra, corners with six equivalent Y(2)Y9Mg3 cuboctahedra, edges with three equivalent Y(1)Y10Mg2 cuboctahedra, edges with three equivalent Y(4)Y11Mg cuboctahedra, edges with four equivalent Y(5)Y10Mg2 cuboctahedra, edges with six equivalent Y(3)Y10Mg2 cuboctahedra, faces with two equivalent Y(2)Y9Mg3 cuboctahedra, faces with three equivalent Y(1)Y10Mg2 cuboctahedra, faces with three equivalent Y(3)Y10Mg2 cuboctahedra, faces with three equivalent Y(4)Y11Mg cuboctahedra, and faces with four equivalent Y(5)Y10Mg2 cuboctahedra. The Y(2)-Y(5) bond length is 3.45 Å. Both Y(2)-Y(2) bond lengths are 3.63 Å. Both Y(2)-Y(3) bond lengths are 3.64 Å. Both Y(2)-Y(4) bond lengths are 3.48 Å. In the third Y site, Y(3) is bonded to two equivalent Mg(1), one Y(1), two equivalent Y(2), two equivalent Y(3), two equivalent Y(5), and three equivalent Y(4) atoms to form distorted YY10Mg2 cuboctahedra that share corners with six equivalent Y(3)Y10Mg2 cuboctahedra, corners with six equivalent Y(5)Y10Mg2 cuboctahedra, edges with two equivalent Y(4)Y11Mg cuboctahedra, edges with three equivalent Y(5)Y10Mg2 cuboctahedra, edges with four equivalent Y(1)Y10Mg2 cuboctahedra, edges with six equivalent Y(2)Y9Mg3 cuboctahedra, faces with two equivalent Y(3)Y10Mg2 cuboctahedra, faces with three equivalent Y(5)Y10Mg2 cuboctahedra, faces with three equivalent Y(2)Y9Mg3 cuboctahedra, faces with four equivalent Y(1)Y10Mg2 cuboctahedra, and faces with five equivalent Y(4)Y11Mg cuboctahedra. Both Y(3)-Y(3) bond lengths are 3.63 Å. Both Y(3)-Y(5) bond lengths are 3.63 Å. There is one shorter (3.55 Å) and two longer (3.57 Å) Y(3)-Y(4) bond lengths. In the fourth Y site, Y(4) is bonded to one Mg(1), two equivalent Y(1), two equivalent Y(2), two equivalent Y(4), two equivalent Y(5), and three equivalent Y(3) atoms to form YY11Mg cuboctahedra that share corners with six equivalent Y(1)Y10Mg2 cuboctahedra, corners with six equivalent Y(4)Y11Mg cuboctahedra, corners with six equivalent Y(2)Y9Mg3 cuboctahedra, edges with two equivalent Y(3)Y10Mg2 cuboctahedra, edges with three equivalent Y(1)Y10Mg2 cuboctahedra, edges with three equivalent Y(2)Y9Mg3 cuboctahedra, edges with six equivalent Y(5)Y10Mg2 cuboctahedra, faces with two equivalent Y(4)Y11Mg cuboctahedra, faces with three equivalent Y(1)Y10Mg2 cuboctahedra, faces with three equivalent Y(5)Y10Mg2 cuboctahedra, faces with three equivalent Y(2)Y9Mg3 cuboctahedra, and faces with five equivalent Y(3)Y10Mg2 cuboctahedra. Both Y(4)-Y(4) bond lengths are 3.63 Å. Both Y(4)-Y(5) bond lengths are 3.50 Å. In the fifth Y site, Y(5) is bonded to two equivalent Mg(1), one Y(2), two equivalent Y(3), two equivalent Y(4), two equivalent Y(5), and three equivalent Y(1) atoms to form YY10Mg2 cuboctahedra that share corners with six equivalent Y(3)Y10Mg2 cuboctahedra, corners with six equivalent Y(5)Y10Mg2 cuboctahedra, edges with two equivalent Y(1)Y10Mg2 cuboctahedra, edges with three equivalent Y(3)Y10Mg2 cuboctahedra, edges with four equivalent Y(2)Y9Mg3 cuboctahedra, edges with six equivalent Y(4)Y11Mg cuboctahedra, faces with two equivalent Y(5)Y10Mg2 cuboctahedra, faces with three equivalent Y(3)Y10Mg2 cuboctahedra, faces with three equivalent Y(4)Y11Mg cuboctahedra, faces with four equivalent Y(2)Y9Mg3 cuboctahedra, and faces with five equivalent Y(1)Y10Mg2 cuboctahedra. Both Y(5)-Y(5) bond lengths are 3.63 Å.