MgTh9YO20 is alpha bismuth trifluoride-derived structured and crystallizes in the triclinic P1 space group. Mg(1) is bonded in a 4-coordinate geometry to one O(13), one O(16), one O(2), and one O(9) atom. There are nine inequivalent Th sites. In the first Th site, Th(1) is bonded in a body-centered cubic geometry to one O(1), one O(10), one O(13), one O(17), one O(20), one O(3), one O(5), and one O(7) atom. In the second Th site, Th(2) is bonded in a body-centered cubic geometry to one O(10), one O(14), one O(15), one O(16), one O(4), one O(6), one O(7), and one O(9) atom. In the third Th site, Th(3) is bonded in a body-centered cubic geometry to one O(1), one O(12), one O(17), one O(19), one O(2), one O(6), one O(8), and one O(9) atom. In the fourth Th site, Th(4) is bonded in a body-centered cubic geometry to one O(1), one O(11), one O(12), one O(13), one O(16), one O(18), one O(3), and one O(7) atom. In the fifth Th site, Th(5) is bonded in a body-centered cubic geometry to one O(10), one O(11), one O(13), one O(14), one O(19), one O(2), one O(20), and one O(5) atom. In the sixth Th site, Th(6) is bonded in a body-centered cubic geometry to one O(12), one O(14), one O(15), one O(17), one O(2), one O(3), one O(4), and one O(6) atom. In the seventh Th site, Th(7) is bonded in a body-centered cubic geometry to one O(1), one O(15), one O(17), one O(18), one O(20), one O(5), one O(8), and one O(9) atom. In the eighth Th site, Th(8) is bonded in a body-centered cubic geometry to one O(11), one O(14), one O(16), one O(18), one O(19), one O(5), one O(6), and one O(7) atom. In the ninth Th site, Th(9) is bonded in a body-centered cubic geometry to one O(11), one O(12), one O(15), one O(18), one O(20), one O(3), one O(4), and one O(8) atom. Y(1) is bonded in a 4-coordinate geometry to one O(10), one O(13), one O(16), one O(19), one O(2), one O(4), one O(8), and one O(9) atom. There are twenty inequivalent O sites. In the first O site, O(1) is bonded to one Th(1), one Th(3), one Th(4), and one Th(7) atom to form OTh4 tetrahedra that share  a cornercorner with one O(11)Th4 tetrahedra,  a cornercorner with one O(15)Th4 tetrahedra,  a cornercorner with one O(17)Th4 tetrahedra,  a cornercorner with one O(6)Th4 tetrahedra,  a cornercorner with one O(10)YTh3 tetrahedra,  a cornercorner with one O(19)YTh3 tetrahedra, corners with two equivalent O(3)Th4 tetrahedra, corners with two equivalent O(5)Th4 tetrahedra, corners with two equivalent O(8)YTh3 tetrahedra,  an edgeedge with one O(12)Th4 tetrahedra,  an edgeedge with one O(17)Th4 tetrahedra,  an edgeedge with one O(18)Th4 tetrahedra,  an edgeedge with one O(20)Th4 tetrahedra, and  an edgeedge with one O(7)Th4 tetrahedra. In the second O site, O(2) is bonded in a 5-coordinate geometry to one Mg(1), one Th(3), one Th(5), one Th(6), and one Y(1) atom. In the third O site, O(3) is bonded to one Th(1), one Th(4), one Th(6), and one Th(9) atom to form OTh4 tetrahedra that share  a cornercorner with one O(12)Th4 tetrahedra,  a cornercorner with one O(14)Th4 tetrahedra,  a cornercorner with one O(5)Th4 tetrahedra,  a cornercorner with one O(6)Th4 tetrahedra,  a cornercorner with one O(10)YTh3 tetrahedra,  a cornercorner with one O(8)YTh3 tetrahedra, corners with two equivalent O(1)Th4 tetrahedra, corners with two equivalent O(11)Th4 tetrahedra, corners with two equivalent O(15)Th4 tetrahedra, corners with two equivalent O(7)Th4 tetrahedra,  an edgeedge with one O(12)Th4 tetrahedra,  an edgeedge with one O(17)Th4 tetrahedra,  an edgeedge with one O(18)Th4 tetrahedra,  an edgeedge with one O(20)Th4 tetrahedra, and  an edgeedge with one O(4)YTh3 tetrahedra. In the fourth O site, O(4) is bonded to one Th(2), one Th(6), one Th(9), and one Y(1) atom to form OYTh3 tetrahedra that share  a cornercorner with one O(11)Th4 tetrahedra,  a cornercorner with one O(15)Th4 tetrahedra,  a cornercorner with one O(17)Th4 tetrahedra,  a cornercorner with one O(18)Th4 tetrahedra,  a cornercorner with one O(20)Th4 tetrahedra,  a cornercorner with one O(7)Th4 tetrahedra,  a cornercorner with one O(19)YTh3 tetrahedra, corners with two equivalent O(12)Th4 tetrahedra, corners with two equivalent O(14)Th4 tetrahedra,  an edgeedge with one O(15)Th4 tetrahedra,  an edgeedge with one O(3)Th4 tetrahedra,  an edgeedge with one O(6)Th4 tetrahedra,  an edgeedge with one O(10)YTh3 tetrahedra, and  an edgeedge with one O(8)YTh3 tetrahedra. In the fifth O site, O(5) is bonded to one Th(1), one Th(5), one Th(7), and one Th(8) atom to form OTh4 tetrahedra that share  a cornercorner with one O(15)Th4 tetrahedra,  a cornercorner with one O(20)Th4 tetrahedra,  a cornercorner with one O(3)Th4 tetrahedra,  a cornercorner with one O(6)Th4 tetrahedra,  a cornercorner with one O(8)YTh3 tetrahedra, corners with two equivalent O(1)Th4 tetrahedra, corners with two equivalent O(11)Th4 tetrahedra, corners with two equivalent O(10)YTh3 tetrahedra, corners with two equivalent O(19)YTh3 tetrahedra,  an edgeedge with one O(14)Th4 tetrahedra,  an edgeedge with one O(17)Th4 tetrahedra,  an edgeedge with one O(18)Th4 tetrahedra,  an edgeedge with one O(20)Th4 tetrahedra, and  an edgeedge with one O(7)Th4 tetrahedra. In the sixth O site, O(6) is bonded to one Th(2), one Th(3), one Th(6), and one Th(8) atom to form OTh4 tetrahedra that share  a cornercorner with one O(1)Th4 tetrahedra,  a cornercorner with one O(11)Th4 tetrahedra,  a cornercorner with one O(14)Th4 tetrahedra,  a cornercorner with one O(18)Th4 tetrahedra,  a cornercorner with one O(3)Th4 tetrahedra,  a cornercorner with one O(5)Th4 tetrahedra,  a cornercorner with one O(10)YTh3 tetrahedra,  a cornercorner with one O(8)YTh3 tetrahedra, corners with two equivalent O(12)Th4 tetrahedra, corners with two equivalent O(15)Th4 tetrahedra,  an edgeedge with one O(14)Th4 tetrahedra,  an edgeedge with one O(17)Th4 tetrahedra,  an edgeedge with one O(7)Th4 tetrahedra,  an edgeedge with one O(19)YTh3 tetrahedra, and  an edgeedge with one O(4)YTh3 tetrahedra. In the seventh O site, O(7) is bonded to one Th(1), one Th(2), one Th(4), and one Th(8) atom to form OTh4 tetrahedra that share  a cornercorner with one O(12)Th4 tetrahedra,  a cornercorner with one O(15)Th4 tetrahedra,  a cornercorner with one O(17)Th4 tetrahedra,  a cornercorner with one O(20)Th4 tetrahedra,  a cornercorner with one O(19)YTh3 tetrahedra,  a cornercorner with one O(4)YTh3 tetrahedra, corners with two equivalent O(14)Th4 tetrahedra, corners with two equivalent O(18)Th4 tetrahedra, corners with two equivalent O(3)Th4 tetrahedra,  an edgeedge with one O(1)Th4 tetrahedra,  an edgeedge with one O(11)Th4 tetrahedra,  an edgeedge with one O(5)Th4 tetrahedra,  an edgeedge with one O(6)Th4 tetrahedra, and  an edgeedge with one O(10)YTh3 tetrahedra. In the eighth O site, O(8) is bonded to one Th(3), one Th(7), one Th(9), and one Y(1) atom to form OYTh3 tetrahedra that share  a cornercorner with one O(11)Th4 tetrahedra,  a cornercorner with one O(3)Th4 tetrahedra,  a cornercorner with one O(5)Th4 tetrahedra,  a cornercorner with one O(6)Th4 tetrahedra,  a cornercorner with one O(10)YTh3 tetrahedra, corners with two equivalent O(1)Th4 tetrahedra, corners with two equivalent O(15)Th4 tetrahedra, corners with two equivalent O(20)Th4 tetrahedra,  an edgeedge with one O(12)Th4 tetrahedra,  an edgeedge with one O(17)Th4 tetrahedra,  an edgeedge with one O(18)Th4 tetrahedra,  an edgeedge with one O(19)YTh3 tetrahedra, and  an edgeedge with one O(4)YTh3 tetrahedra. In the ninth O site, O(9) is bonded in a 5-coordinate geometry to one Mg(1), one Th(2), one Th(3), one Th(7), and one Y(1) atom. In the tenth O site, O(10) is bonded to one Th(1), one Th(2), one Th(5), and one Y(1) atom to form OYTh3 tetrahedra that share  a cornercorner with one O(1)Th4 tetrahedra,  a cornercorner with one O(11)Th4 tetrahedra,  a cornercorner with one O(15)Th4 tetrahedra,  a cornercorner with one O(17)Th4 tetrahedra,  a cornercorner with one O(3)Th4 tetrahedra,  a cornercorner with one O(6)Th4 tetrahedra,  a cornercorner with one O(8)YTh3 tetrahedra, corners with two equivalent O(5)Th4 tetrahedra,  an edgeedge with one O(14)Th4 tetrahedra,  an edgeedge with one O(20)Th4 tetrahedra,  an edgeedge with one O(7)Th4 tetrahedra,  an edgeedge with one O(19)YTh3 tetrahedra, and  an edgeedge with one O(4)YTh3 tetrahedra. In the eleventh O site, O(11) is bonded to one Th(4), one Th(5), one Th(8), and one Th(9) atom to form OTh4 tetrahedra that share  a cornercorner with one O(1)Th4 tetrahedra,  a cornercorner with one O(15)Th4 tetrahedra,  a cornercorner with one O(18)Th4 tetrahedra,  a cornercorner with one O(6)Th4 tetrahedra,  a cornercorner with one O(10)YTh3 tetrahedra,  a cornercorner with one O(4)YTh3 tetrahedra,  a cornercorner with one O(8)YTh3 tetrahedra, corners with two equivalent O(14)Th4 tetrahedra, corners with two equivalent O(3)Th4 tetrahedra, corners with two equivalent O(5)Th4 tetrahedra,  an edgeedge with one O(12)Th4 tetrahedra,  an edgeedge with one O(18)Th4 tetrahedra,  an edgeedge with one O(20)Th4 tetrahedra,  an edgeedge with one O(7)Th4 tetrahedra, and  an edgeedge with one O(19)YTh3 tetrahedra. In the twelfth O site, O(12) is bonded to one Th(3), one Th(4), one Th(6), and one Th(9) atom to form OTh4 tetrahedra that share  a cornercorner with one O(14)Th4 tetrahedra,  a cornercorner with one O(20)Th4 tetrahedra,  a cornercorner with one O(3)Th4 tetrahedra,  a cornercorner with one O(7)Th4 tetrahedra,  a cornercorner with one O(19)YTh3 tetrahedra, corners with two equivalent O(17)Th4 tetrahedra, corners with two equivalent O(18)Th4 tetrahedra, corners with two equivalent O(6)Th4 tetrahedra, corners with two equivalent O(4)YTh3 tetrahedra,  an edgeedge with one O(1)Th4 tetrahedra,  an edgeedge with one O(11)Th4 tetrahedra,  an edgeedge with one O(15)Th4 tetrahedra,  an edgeedge with one O(3)Th4 tetrahedra, and  an edgeedge with one O(8)YTh3 tetrahedra. In the thirteenth O site, O(13) is bonded in a 5-coordinate geometry to one Mg(1), one Th(1), one Th(4), one Th(5), and one Y(1) atom. In the fourteenth O site, O(14) is bonded to one Th(2), one Th(5), one Th(6), and one Th(8) atom to form OTh4 tetrahedra that share  a cornercorner with one O(12)Th4 tetrahedra,  a cornercorner with one O(17)Th4 tetrahedra,  a cornercorner with one O(18)Th4 tetrahedra,  a cornercorner with one O(20)Th4 tetrahedra,  a cornercorner with one O(3)Th4 tetrahedra,  a cornercorner with one O(6)Th4 tetrahedra, corners with two equivalent O(11)Th4 tetrahedra, corners with two equivalent O(7)Th4 tetrahedra, corners with two equivalent O(19)YTh3 tetrahedra, corners with two equivalent O(4)YTh3 tetrahedra,  an edgeedge with one O(15)Th4 tetrahedra,  an edgeedge with one O(5)Th4 tetrahedra,  an edgeedge with one O(6)Th4 tetrahedra, and  an edgeedge with one O(10)YTh3 tetrahedra. In the fifteenth O site, O(15) is bonded to one Th(2), one Th(6), one Th(7), and one Th(9) atom to form OTh4 tetrahedra that share  a cornercorner with one O(1)Th4 tetrahedra,  a cornercorner with one O(11)Th4 tetrahedra,  a cornercorner with one O(5)Th4 tetrahedra,  a cornercorner with one O(7)Th4 tetrahedra,  a cornercorner with one O(10)YTh3 tetrahedra,  a cornercorner with one O(4)YTh3 tetrahedra, corners with two equivalent O(18)Th4 tetrahedra, corners with two equivalent O(3)Th4 tetrahedra, corners with two equivalent O(6)Th4 tetrahedra, corners with two equivalent O(8)YTh3 tetrahedra,  an edgeedge with one O(12)Th4 tetrahedra,  an edgeedge with one O(14)Th4 tetrahedra,  an edgeedge with one O(17)Th4 tetrahedra,  an edgeedge with one O(20)Th4 tetrahedra, and  an edgeedge with one O(4)YTh3 tetrahedra. In the sixteenth O site, O(16) is bonded in a 5-coordinate geometry to one Mg(1), one Th(2), one Th(4), one Th(8), and one Y(1) atom. In the seventeenth O site, O(17) is bonded to one Th(1), one Th(3), one Th(6), and one Th(7) atom to form OTh4 tetrahedra that share  a cornercorner with one O(1)Th4 tetrahedra,  a cornercorner with one O(14)Th4 tetrahedra,  a cornercorner with one O(18)Th4 tetrahedra,  a cornercorner with one O(7)Th4 tetrahedra,  a cornercorner with one O(10)YTh3 tetrahedra,  a cornercorner with one O(19)YTh3 tetrahedra,  a cornercorner with one O(4)YTh3 tetrahedra, corners with two equivalent O(12)Th4 tetrahedra, corners with two equivalent O(20)Th4 tetrahedra,  an edgeedge with one O(1)Th4 tetrahedra,  an edgeedge with one O(15)Th4 tetrahedra,  an edgeedge with one O(3)Th4 tetrahedra,  an edgeedge with one O(5)Th4 tetrahedra,  an edgeedge with one O(6)Th4 tetrahedra, and  an edgeedge with one O(8)YTh3 tetrahedra. In the eighteenth O site, O(18) is bonded to one Th(4), one Th(7), one Th(8), and one Th(9) atom to form OTh4 tetrahedra that share  a cornercorner with one O(11)Th4 tetrahedra,  a cornercorner with one O(14)Th4 tetrahedra,  a cornercorner with one O(17)Th4 tetrahedra,  a cornercorner with one O(6)Th4 tetrahedra,  a cornercorner with one O(19)YTh3 tetrahedra,  a cornercorner with one O(4)YTh3 tetrahedra, corners with two equivalent O(12)Th4 tetrahedra, corners with two equivalent O(15)Th4 tetrahedra, corners with two equivalent O(20)Th4 tetrahedra, corners with two equivalent O(7)Th4 tetrahedra,  an edgeedge with one O(1)Th4 tetrahedra,  an edgeedge with one O(11)Th4 tetrahedra,  an edgeedge with one O(3)Th4 tetrahedra,  an edgeedge with one O(5)Th4 tetrahedra, and  an edgeedge with one O(8)YTh3 tetrahedra. In the nineteenth O site, O(19) is bonded to one Th(3), one Th(5), one Th(8), and one Y(1) atom to form distorted OYTh3 tetrahedra that share  a cornercorner with one O(1)Th4 tetrahedra,  a cornercorner with one O(12)Th4 tetrahedra,  a cornercorner with one O(17)Th4 tetrahedra,  a cornercorner with one O(18)Th4 tetrahedra,  a cornercorner with one O(20)Th4 tetrahedra,  a cornercorner with one O(7)Th4 tetrahedra,  a cornercorner with one O(4)YTh3 tetrahedra, corners with two equivalent O(14)Th4 tetrahedra, corners with two equivalent O(5)Th4 tetrahedra,  an edgeedge with one O(11)Th4 tetrahedra,  an edgeedge with one O(6)Th4 tetrahedra,  an edgeedge with one O(10)YTh3 tetrahedra, and  an edgeedge with one O(8)YTh3 tetrahedra. In the twentieth O site, O(20) is bonded to one Th(1), one Th(5), one Th(7), and one Th(9) atom to form OTh4 tetrahedra that share  a cornercorner with one O(12)Th4 tetrahedra,  a cornercorner with one O(14)Th4 tetrahedra,  a cornercorner with one O(5)Th4 tetrahedra,  a cornercorner with one O(7)Th4 tetrahedra,  a cornercorner with one O(19)YTh3 tetrahedra,  a cornercorner with one O(4)YTh3 tetrahedra, corners with two equivalent O(17)Th4 tetrahedra, corners with two equivalent O(18)Th4 tetrahedra, corners with two equivalent O(8)YTh3 tetrahedra,  an edgeedge with one O(1)Th4 tetrahedra,  an edgeedge with one O(11)Th4 tetrahedra,  an edgeedge with one O(15)Th4 tetrahedra,  an edgeedge with one O(3)Th4 tetrahedra,  an edgeedge with one O(5)Th4 tetrahedra, and  an edgeedge with one O(10)YTh3 tetrahedra.
MgTh9YO20 is alpha bismuth trifluoride-derived structured and crystallizes in the triclinic P1 space group. Mg(1) is bonded in a 4-coordinate geometry to one O(13), one O(16), one O(2), and one O(9) atom. The Mg(1)-O(13) bond length is 2.07 Å. The Mg(1)-O(16) bond length is 2.09 Å. The Mg(1)-O(2) bond length is 2.06 Å. The Mg(1)-O(9) bond length is 2.11 Å. There are nine inequivalent Th sites. In the first Th site, Th(1) is bonded in a body-centered cubic geometry to one O(1), one O(10), one O(13), one O(17), one O(20), one O(3), one O(5), and one O(7) atom. The Th(1)-O(1) bond length is 2.50 Å. The Th(1)-O(10) bond length is 2.47 Å. The Th(1)-O(13) bond length is 2.43 Å. The Th(1)-O(17) bond length is 2.44 Å. The Th(1)-O(20) bond length is 2.46 Å. The Th(1)-O(3) bond length is 2.45 Å. The Th(1)-O(5) bond length is 2.44 Å. The Th(1)-O(7) bond length is 2.36 Å. In the second Th site, Th(2) is bonded in a body-centered cubic geometry to one O(10), one O(14), one O(15), one O(16), one O(4), one O(6), one O(7), and one O(9) atom. The Th(2)-O(10) bond length is 2.40 Å. The Th(2)-O(14) bond length is 2.42 Å. The Th(2)-O(15) bond length is 2.43 Å. The Th(2)-O(16) bond length is 2.47 Å. The Th(2)-O(4) bond length is 2.39 Å. The Th(2)-O(6) bond length is 2.50 Å. The Th(2)-O(7) bond length is 2.52 Å. The Th(2)-O(9) bond length is 2.48 Å. In the third Th site, Th(3) is bonded in a body-centered cubic geometry to one O(1), one O(12), one O(17), one O(19), one O(2), one O(6), one O(8), and one O(9) atom. The Th(3)-O(1) bond length is 2.37 Å. The Th(3)-O(12) bond length is 2.42 Å. The Th(3)-O(17) bond length is 2.40 Å. The Th(3)-O(19) bond length is 2.47 Å. The Th(3)-O(2) bond length is 2.54 Å. The Th(3)-O(6) bond length is 2.49 Å. The Th(3)-O(8) bond length is 2.39 Å. The Th(3)-O(9) bond length is 2.49 Å. In the fourth Th site, Th(4) is bonded in a body-centered cubic geometry to one O(1), one O(11), one O(12), one O(13), one O(16), one O(18), one O(3), and one O(7) atom. The Th(4)-O(1) bond length is 2.40 Å. The Th(4)-O(11) bond length is 2.53 Å. The Th(4)-O(12) bond length is 2.40 Å. The Th(4)-O(13) bond length is 2.50 Å. The Th(4)-O(16) bond length is 2.49 Å. The Th(4)-O(18) bond length is 2.39 Å. The Th(4)-O(3) bond length is 2.41 Å. The Th(4)-O(7) bond length is 2.51 Å. In the fifth Th site, Th(5) is bonded in a body-centered cubic geometry to one O(10), one O(11), one O(13), one O(14), one O(19), one O(2), one O(20), and one O(5) atom. The Th(5)-O(10) bond length is 2.37 Å. The Th(5)-O(11) bond length is 2.50 Å. The Th(5)-O(13) bond length is 2.48 Å. The Th(5)-O(14) bond length is 2.40 Å. The Th(5)-O(19) bond length is 2.52 Å. The Th(5)-O(2) bond length is 2.53 Å. The Th(5)-O(20) bond length is 2.40 Å. The Th(5)-O(5) bond length is 2.37 Å. In the sixth Th site, Th(6) is bonded in a body-centered cubic geometry to one O(12), one O(14), one O(15), one O(17), one O(2), one O(3), one O(4), and one O(6) atom. The Th(6)-O(12) bond length is 2.43 Å. The Th(6)-O(14) bond length is 2.45 Å. The Th(6)-O(15) bond length is 2.46 Å. The Th(6)-O(17) bond length is 2.50 Å. The Th(6)-O(2) bond length is 2.45 Å. The Th(6)-O(3) bond length is 2.46 Å. The Th(6)-O(4) bond length is 2.47 Å. The Th(6)-O(6) bond length is 2.36 Å. In the seventh Th site, Th(7) is bonded in a body-centered cubic geometry to one O(1), one O(15), one O(17), one O(18), one O(20), one O(5), one O(8), and one O(9) atom. The Th(7)-O(1) bond length is 2.44 Å. The Th(7)-O(15) bond length is 2.44 Å. The Th(7)-O(17) bond length is 2.43 Å. The Th(7)-O(18) bond length is 2.45 Å. The Th(7)-O(20) bond length is 2.44 Å. The Th(7)-O(5) bond length is 2.45 Å. The Th(7)-O(8) bond length is 2.43 Å. The Th(7)-O(9) bond length is 2.47 Å. In the eighth Th site, Th(8) is bonded in a body-centered cubic geometry to one O(11), one O(14), one O(16), one O(18), one O(19), one O(5), one O(6), and one O(7) atom. The Th(8)-O(11) bond length is 2.44 Å. The Th(8)-O(14) bond length is 2.47 Å. The Th(8)-O(16) bond length is 2.52 Å. The Th(8)-O(18) bond length is 2.49 Å. The Th(8)-O(19) bond length is 2.43 Å. The Th(8)-O(5) bond length is 2.51 Å. The Th(8)-O(6) bond length is 2.47 Å. The Th(8)-O(7) bond length is 2.46 Å. In the ninth Th site, Th(9) is bonded in a body-centered cubic geometry to one O(11), one O(12), one O(15), one O(18), one O(20), one O(3), one O(4), and one O(8) atom. The Th(9)-O(11) bond length is 2.35 Å. The Th(9)-O(12) bond length is 2.48 Å. The Th(9)-O(15) bond length is 2.46 Å. The Th(9)-O(18) bond length is 2.46 Å. The Th(9)-O(20) bond length is 2.44 Å. The Th(9)-O(3) bond length is 2.44 Å. The Th(9)-O(4) bond length is 2.41 Å. The Th(9)-O(8) bond length is 2.44 Å. Y(1) is bonded in a 4-coordinate geometry to one O(10), one O(13), one O(16), one O(19), one O(2), one O(4), one O(8), and one O(9) atom. The Y(1)-O(10) bond length is 2.27 Å. The Y(1)-O(13) bond length is 2.76 Å. The Y(1)-O(16) bond length is 2.69 Å. The Y(1)-O(19) bond length is 2.21 Å. The Y(1)-O(2) bond length is 2.68 Å. The Y(1)-O(4) bond length is 2.24 Å. The Y(1)-O(8) bond length is 2.25 Å. The Y(1)-O(9) bond length is 2.65 Å. There are twenty inequivalent O sites. In the first O site, O(1) is bonded to one Th(1), one Th(3), one Th(4), and one Th(7) atom to form OTh4 tetrahedra that share  a cornercorner with one O(11)Th4 tetrahedra,  a cornercorner with one O(15)Th4 tetrahedra,  a cornercorner with one O(17)Th4 tetrahedra,  a cornercorner with one O(6)Th4 tetrahedra,  a cornercorner with one O(10)YTh3 tetrahedra,  a cornercorner with one O(19)YTh3 tetrahedra, corners with two equivalent O(3)Th4 tetrahedra, corners with two equivalent O(5)Th4 tetrahedra, corners with two equivalent O(8)YTh3 tetrahedra,  an edgeedge with one O(12)Th4 tetrahedra,  an edgeedge with one O(17)Th4 tetrahedra,  an edgeedge with one O(18)Th4 tetrahedra,  an edgeedge with one O(20)Th4 tetrahedra, and  an edgeedge with one O(7)Th4 tetrahedra. In the second O site, O(2) is bonded in a 5-coordinate geometry to one Mg(1), one Th(3), one Th(5), one Th(6), and one Y(1) atom. In the third O site, O(3) is bonded to one Th(1), one Th(4), one Th(6), and one Th(9) atom to form OTh4 tetrahedra that share  a cornercorner with one O(12)Th4 tetrahedra,  a cornercorner with one O(14)Th4 tetrahedra,  a cornercorner with one O(5)Th4 tetrahedra,  a cornercorner with one O(6)Th4 tetrahedra,  a cornercorner with one O(10)YTh3 tetrahedra,  a cornercorner with one O(8)YTh3 tetrahedra, corners with two equivalent O(1)Th4 tetrahedra, corners with two equivalent O(11)Th4 tetrahedra, corners with two equivalent O(15)Th4 tetrahedra, corners with two equivalent O(7)Th4 tetrahedra,  an edgeedge with one O(12)Th4 tetrahedra,  an edgeedge with one O(17)Th4 tetrahedra,  an edgeedge with one O(18)Th4 tetrahedra,  an edgeedge with one O(20)Th4 tetrahedra, and  an edgeedge with one O(4)YTh3 tetrahedra. In the fourth O site, O(4) is bonded to one Th(2), one Th(6), one Th(9), and one Y(1) atom to form OYTh3 tetrahedra that share  a cornercorner with one O(11)Th4 tetrahedra,  a cornercorner with one O(15)Th4 tetrahedra,  a cornercorner with one O(17)Th4 tetrahedra,  a cornercorner with one O(18)Th4 tetrahedra,  a cornercorner with one O(20)Th4 tetrahedra,  a cornercorner with one O(7)Th4 tetrahedra,  a cornercorner with one O(19)YTh3 tetrahedra, corners with two equivalent O(12)Th4 tetrahedra, corners with two equivalent O(14)Th4 tetrahedra,  an edgeedge with one O(15)Th4 tetrahedra,  an edgeedge with one O(3)Th4 tetrahedra,  an edgeedge with one O(6)Th4 tetrahedra,  an edgeedge with one O(10)YTh3 tetrahedra, and  an edgeedge with one O(8)YTh3 tetrahedra. In the fifth O site, O(5) is bonded to one Th(1), one Th(5), one Th(7), and one Th(8) atom to form OTh4 tetrahedra that share  a cornercorner with one O(15)Th4 tetrahedra,  a cornercorner with one O(20)Th4 tetrahedra,  a cornercorner with one O(3)Th4 tetrahedra,  a cornercorner with one O(6)Th4 tetrahedra,  a cornercorner with one O(8)YTh3 tetrahedra, corners with two equivalent O(1)Th4 tetrahedra, corners with two equivalent O(11)Th4 tetrahedra, corners with two equivalent O(10)YTh3 tetrahedra, corners with two equivalent O(19)YTh3 tetrahedra,  an edgeedge with one O(14)Th4 tetrahedra,  an edgeedge with one O(17)Th4 tetrahedra,  an edgeedge with one O(18)Th4 tetrahedra,  an edgeedge with one O(20)Th4 tetrahedra, and  an edgeedge with one O(7)Th4 tetrahedra. In the sixth O site, O(6) is bonded to one Th(2), one Th(3), one Th(6), and one Th(8) atom to form OTh4 tetrahedra that share  a cornercorner with one O(1)Th4 tetrahedra,  a cornercorner with one O(11)Th4 tetrahedra,  a cornercorner with one O(14)Th4 tetrahedra,  a cornercorner with one O(18)Th4 tetrahedra,  a cornercorner with one O(3)Th4 tetrahedra,  a cornercorner with one O(5)Th4 tetrahedra,  a cornercorner with one O(10)YTh3 tetrahedra,  a cornercorner with one O(8)YTh3 tetrahedra, corners with two equivalent O(12)Th4 tetrahedra, corners with two equivalent O(15)Th4 tetrahedra,  an edgeedge with one O(14)Th4 tetrahedra,  an edgeedge with one O(17)Th4 tetrahedra,  an edgeedge with one O(7)Th4 tetrahedra,  an edgeedge with one O(19)YTh3 tetrahedra, and  an edgeedge with one O(4)YTh3 tetrahedra. In the seventh O site, O(7) is bonded to one Th(1), one Th(2), one Th(4), and one Th(8) atom to form OTh4 tetrahedra that share  a cornercorner with one O(12)Th4 tetrahedra,  a cornercorner with one O(15)Th4 tetrahedra,  a cornercorner with one O(17)Th4 tetrahedra,  a cornercorner with one O(20)Th4 tetrahedra,  a cornercorner with one O(19)YTh3 tetrahedra,  a cornercorner with one O(4)YTh3 tetrahedra, corners with two equivalent O(14)Th4 tetrahedra, corners with two equivalent O(18)Th4 tetrahedra, corners with two equivalent O(3)Th4 tetrahedra,  an edgeedge with one O(1)Th4 tetrahedra,  an edgeedge with one O(11)Th4 tetrahedra,  an edgeedge with one O(5)Th4 tetrahedra,  an edgeedge with one O(6)Th4 tetrahedra, and  an edgeedge with one O(10)YTh3 tetrahedra. In the eighth O site, O(8) is bonded to one Th(3), one Th(7), one Th(9), and one Y(1) atom to form OYTh3 tetrahedra that share  a cornercorner with one O(11)Th4 tetrahedra,  a cornercorner with one O(3)Th4 tetrahedra,  a cornercorner with one O(5)Th4 tetrahedra,  a cornercorner with one O(6)Th4 tetrahedra,  a cornercorner with one O(10)YTh3 tetrahedra, corners with two equivalent O(1)Th4 tetrahedra, corners with two equivalent O(15)Th4 tetrahedra, corners with two equivalent O(20)Th4 tetrahedra,  an edgeedge with one O(12)Th4 tetrahedra,  an edgeedge with one O(17)Th4 tetrahedra,  an edgeedge with one O(18)Th4 tetrahedra,  an edgeedge with one O(19)YTh3 tetrahedra, and  an edgeedge with one O(4)YTh3 tetrahedra. In the ninth O site, O(9) is bonded in a 5-coordinate geometry to one Mg(1), one Th(2), one Th(3), one Th(7), and one Y(1) atom. In the tenth O site, O(10) is bonded to one Th(1), one Th(2), one Th(5), and one Y(1) atom to form OYTh3 tetrahedra that share  a cornercorner with one O(1)Th4 tetrahedra,  a cornercorner with one O(11)Th4 tetrahedra,  a cornercorner with one O(15)Th4 tetrahedra,  a cornercorner with one O(17)Th4 tetrahedra,  a cornercorner with one O(3)Th4 tetrahedra,  a cornercorner with one O(6)Th4 tetrahedra,  a cornercorner with one O(8)YTh3 tetrahedra, corners with two equivalent O(5)Th4 tetrahedra,  an edgeedge with one O(14)Th4 tetrahedra,  an edgeedge with one O(20)Th4 tetrahedra,  an edgeedge with one O(7)Th4 tetrahedra,  an edgeedge with one O(19)YTh3 tetrahedra, and  an edgeedge with one O(4)YTh3 tetrahedra. In the eleventh O site, O(11) is bonded to one Th(4), one Th(5), one Th(8), and one Th(9) atom to form OTh4 tetrahedra that share  a cornercorner with one O(1)Th4 tetrahedra,  a cornercorner with one O(15)Th4 tetrahedra,  a cornercorner with one O(18)Th4 tetrahedra,  a cornercorner with one O(6)Th4 tetrahedra,  a cornercorner with one O(10)YTh3 tetrahedra,  a cornercorner with one O(4)YTh3 tetrahedra,  a cornercorner with one O(8)YTh3 tetrahedra, corners with two equivalent O(14)Th4 tetrahedra, corners with two equivalent O(3)Th4 tetrahedra, corners with two equivalent O(5)Th4 tetrahedra,  an edgeedge with one O(12)Th4 tetrahedra,  an edgeedge with one O(18)Th4 tetrahedra,  an edgeedge with one O(20)Th4 tetrahedra,  an edgeedge with one O(7)Th4 tetrahedra, and  an edgeedge with one O(19)YTh3 tetrahedra. In the twelfth O site, O(12) is bonded to one Th(3), one Th(4), one Th(6), and one Th(9) atom to form OTh4 tetrahedra that share  a cornercorner with one O(14)Th4 tetrahedra,  a cornercorner with one O(20)Th4 tetrahedra,  a cornercorner with one O(3)Th4 tetrahedra,  a cornercorner with one O(7)Th4 tetrahedra,  a cornercorner with one O(19)YTh3 tetrahedra, corners with two equivalent O(17)Th4 tetrahedra, corners with two equivalent O(18)Th4 tetrahedra, corners with two equivalent O(6)Th4 tetrahedra, corners with two equivalent O(4)YTh3 tetrahedra,  an edgeedge with one O(1)Th4 tetrahedra,  an edgeedge with one O(11)Th4 tetrahedra,  an edgeedge with one O(15)Th4 tetrahedra,  an edgeedge with one O(3)Th4 tetrahedra, and  an edgeedge with one O(8)YTh3 tetrahedra. In the thirteenth O site, O(13) is bonded in a 5-coordinate geometry to one Mg(1), one Th(1), one Th(4), one Th(5), and one Y(1) atom. In the fourteenth O site, O(14) is bonded to one Th(2), one Th(5), one Th(6), and one Th(8) atom to form OTh4 tetrahedra that share  a cornercorner with one O(12)Th4 tetrahedra,  a cornercorner with one O(17)Th4 tetrahedra,  a cornercorner with one O(18)Th4 tetrahedra,  a cornercorner with one O(20)Th4 tetrahedra,  a cornercorner with one O(3)Th4 tetrahedra,  a cornercorner with one O(6)Th4 tetrahedra, corners with two equivalent O(11)Th4 tetrahedra, corners with two equivalent O(7)Th4 tetrahedra, corners with two equivalent O(19)YTh3 tetrahedra, corners with two equivalent O(4)YTh3 tetrahedra,  an edgeedge with one O(15)Th4 tetrahedra,  an edgeedge with one O(5)Th4 tetrahedra,  an edgeedge with one O(6)Th4 tetrahedra, and  an edgeedge with one O(10)YTh3 tetrahedra. In the fifteenth O site, O(15) is bonded to one Th(2), one Th(6), one Th(7), and one Th(9) atom to form OTh4 tetrahedra that share  a cornercorner with one O(1)Th4 tetrahedra,  a cornercorner with one O(11)Th4 tetrahedra,  a cornercorner with one O(5)Th4 tetrahedra,  a cornercorner with one O(7)Th4 tetrahedra,  a cornercorner with one O(10)YTh3 tetrahedra,  a cornercorner with one O(4)YTh3 tetrahedra, corners with two equivalent O(18)Th4 tetrahedra, corners with two equivalent O(3)Th4 tetrahedra, corners with two equivalent O(6)Th4 tetrahedra, corners with two equivalent O(8)YTh3 tetrahedra,  an edgeedge with one O(12)Th4 tetrahedra,  an edgeedge with one O(14)Th4 tetrahedra,  an edgeedge with one O(17)Th4 tetrahedra,  an edgeedge with one O(20)Th4 tetrahedra, and  an edgeedge with one O(4)YTh3 tetrahedra. In the sixteenth O site, O(16) is bonded in a 5-coordinate geometry to one Mg(1), one Th(2), one Th(4), one Th(8), and one Y(1) atom. In the seventeenth O site, O(17) is bonded to one Th(1), one Th(3), one Th(6), and one Th(7) atom to form OTh4 tetrahedra that share  a cornercorner with one O(1)Th4 tetrahedra,  a cornercorner with one O(14)Th4 tetrahedra,  a cornercorner with one O(18)Th4 tetrahedra,  a cornercorner with one O(7)Th4 tetrahedra,  a cornercorner with one O(10)YTh3 tetrahedra,  a cornercorner with one O(19)YTh3 tetrahedra,  a cornercorner with one O(4)YTh3 tetrahedra, corners with two equivalent O(12)Th4 tetrahedra, corners with two equivalent O(20)Th4 tetrahedra,  an edgeedge with one O(1)Th4 tetrahedra,  an edgeedge with one O(15)Th4 tetrahedra,  an edgeedge with one O(3)Th4 tetrahedra,  an edgeedge with one O(5)Th4 tetrahedra,  an edgeedge with one O(6)Th4 tetrahedra, and  an edgeedge with one O(8)YTh3 tetrahedra. In the eighteenth O site, O(18) is bonded to one Th(4), one Th(7), one Th(8), and one Th(9) atom to form OTh4 tetrahedra that share  a cornercorner with one O(11)Th4 tetrahedra,  a cornercorner with one O(14)Th4 tetrahedra,  a cornercorner with one O(17)Th4 tetrahedra,  a cornercorner with one O(6)Th4 tetrahedra,  a cornercorner with one O(19)YTh3 tetrahedra,  a cornercorner with one O(4)YTh3 tetrahedra, corners with two equivalent O(12)Th4 tetrahedra, corners with two equivalent O(15)Th4 tetrahedra, corners with two equivalent O(20)Th4 tetrahedra, corners with two equivalent O(7)Th4 tetrahedra,  an edgeedge with one O(1)Th4 tetrahedra,  an edgeedge with one O(11)Th4 tetrahedra,  an edgeedge with one O(3)Th4 tetrahedra,  an edgeedge with one O(5)Th4 tetrahedra, and  an edgeedge with one O(8)YTh3 tetrahedra. In the nineteenth O site, O(19) is bonded to one Th(3), one Th(5), one Th(8), and one Y(1) atom to form distorted OYTh3 tetrahedra that share  a cornercorner with one O(1)Th4 tetrahedra,  a cornercorner with one O(12)Th4 tetrahedra,  a cornercorner with one O(17)Th4 tetrahedra,  a cornercorner with one O(18)Th4 tetrahedra,  a cornercorner with one O(20)Th4 tetrahedra,  a cornercorner with one O(7)Th4 tetrahedra,  a cornercorner with one O(4)YTh3 tetrahedra, corners with two equivalent O(14)Th4 tetrahedra, corners with two equivalent O(5)Th4 tetrahedra,  an edgeedge with one O(11)Th4 tetrahedra,  an edgeedge with one O(6)Th4 tetrahedra,  an edgeedge with one O(10)YTh3 tetrahedra, and  an edgeedge with one O(8)YTh3 tetrahedra. In the twentieth O site, O(20) is bonded to one Th(1), one Th(5), one Th(7), and one Th(9) atom to form OTh4 tetrahedra that share  a cornercorner with one O(12)Th4 tetrahedra,  a cornercorner with one O(14)Th4 tetrahedra,  a cornercorner with one O(5)Th4 tetrahedra,  a cornercorner with one O(7)Th4 tetrahedra,  a cornercorner with one O(19)YTh3 tetrahedra,  a cornercorner with one O(4)YTh3 tetrahedra, corners with two equivalent O(17)Th4 tetrahedra, corners with two equivalent O(18)Th4 tetrahedra, corners with two equivalent O(8)YTh3 tetrahedra,  an edgeedge with one O(1)Th4 tetrahedra,  an edgeedge with one O(11)Th4 tetrahedra,  an edgeedge with one O(15)Th4 tetrahedra,  an edgeedge with one O(3)Th4 tetrahedra,  an edgeedge with one O(5)Th4 tetrahedra, and  an edgeedge with one O(10)YTh3 tetrahedra.