U7Zr3O20 is Fluorite-derived structured and crystallizes in the monoclinic Cm space group. There are seven inequivalent U sites. In the first U site, U(1) is bonded in a body-centered cubic geometry to one O(1), one O(6), one O(7), one O(9), two equivalent O(13), and two equivalent O(5) atoms. In the second U site, U(2) is bonded in a body-centered cubic geometry to one O(12), one O(3), one O(7), one O(9), two equivalent O(11), and two equivalent O(4) atoms. In the third U site, U(3) is bonded in a body-centered cubic geometry to one O(10), one O(12), one O(14), one O(3), two equivalent O(17), and two equivalent O(8) atoms. In the fourth U site, U(4) is bonded in a body-centered cubic geometry to one O(11), one O(13), one O(17), one O(4), two equivalent O(3), and two equivalent O(9) atoms. In the fifth U site, U(5) is bonded in a body-centered cubic geometry to one O(16), one O(18), one O(19), one O(8), two equivalent O(10), and two equivalent O(15) atoms. In the sixth U site, U(6) is bonded in a body-centered cubic geometry to one O(10), one O(14), one O(15), one O(20), two equivalent O(16), and two equivalent O(19) atoms. In the seventh U site, U(7) is bonded in a body-centered cubic geometry to one O(1), one O(18), one O(19), one O(6), two equivalent O(2), and two equivalent O(20) atoms. There are three inequivalent Zr sites. In the first Zr site, Zr(1) is bonded in a body-centered cubic geometry to one O(13), one O(2), one O(4), one O(5), two equivalent O(1), and two equivalent O(7) atoms. In the second Zr site, Zr(2) is bonded in a body-centered cubic geometry to one O(11), one O(16), one O(17), one O(8), two equivalent O(12), and two equivalent O(14) atoms. In the third Zr site, Zr(3) is bonded in a body-centered cubic geometry to one O(15), one O(2), one O(20), one O(5), two equivalent O(18), and two equivalent O(6) atoms. There are twenty inequivalent O sites. In the first O site, O(1) is bonded to one U(1), one U(7), and two equivalent Zr(1) atoms to form OZr2U2 tetrahedra that share  a cornercorner with one O(19)U4 tetrahedra,  a cornercorner with one O(9)U4 tetrahedra,  a cornercorner with one O(18)Zr2U2 tetrahedra, corners with two equivalent O(1)Zr2U2 tetrahedra, corners with two equivalent O(20)ZrU3 tetrahedra, corners with two equivalent O(4)ZrU3 tetrahedra, corners with three equivalent O(7)Zr2U2 tetrahedra, corners with four equivalent O(5)Zr2U2 tetrahedra,  an edgeedge with one O(6)Zr2U2 tetrahedra,  an edgeedge with one O(7)Zr2U2 tetrahedra, edges with two equivalent O(2)Zr2U2 tetrahedra, and edges with two equivalent O(13)ZrU3 tetrahedra. In the second O site, O(2) is bonded to two equivalent U(7), one Zr(1), and one Zr(3) atom to form OZr2U2 tetrahedra that share  a cornercorner with one O(13)ZrU3 tetrahedra,  a cornercorner with one O(15)ZrU3 tetrahedra,  a cornercorner with one O(4)ZrU3 tetrahedra, corners with two equivalent O(19)U4 tetrahedra, corners with two equivalent O(2)Zr2U2 tetrahedra, corners with two equivalent O(7)Zr2U2 tetrahedra, corners with three equivalent O(20)ZrU3 tetrahedra, corners with four equivalent O(6)Zr2U2 tetrahedra,  an edgeedge with one O(5)Zr2U2 tetrahedra,  an edgeedge with one O(20)ZrU3 tetrahedra, edges with two equivalent O(1)Zr2U2 tetrahedra, and edges with two equivalent O(18)Zr2U2 tetrahedra. In the third O site, O(3) is bonded to one U(2), one U(3), and two equivalent U(4) atoms to form OU4 tetrahedra that share  a cornercorner with one O(10)U4 tetrahedra,  a cornercorner with one O(14)Zr2U2 tetrahedra,  a cornercorner with one O(7)Zr2U2 tetrahedra, corners with two equivalent O(3)U4 tetrahedra, corners with two equivalent O(13)ZrU3 tetrahedra, corners with two equivalent O(8)ZrU3 tetrahedra, corners with three equivalent O(9)U4 tetrahedra, corners with four equivalent O(11)ZrU3 tetrahedra,  an edgeedge with one O(9)U4 tetrahedra,  an edgeedge with one O(12)Zr2U2 tetrahedra, edges with two equivalent O(17)ZrU3 tetrahedra, and edges with two equivalent O(4)ZrU3 tetrahedra. In the fourth O site, O(4) is bonded to one U(4), two equivalent U(2), and one Zr(1) atom to form OZrU3 tetrahedra that share  a cornercorner with one O(2)Zr2U2 tetrahedra,  a cornercorner with one O(5)Zr2U2 tetrahedra,  a cornercorner with one O(17)ZrU3 tetrahedra, corners with two equivalent O(1)Zr2U2 tetrahedra, corners with two equivalent O(12)Zr2U2 tetrahedra, corners with two equivalent O(4)ZrU3 tetrahedra, corners with three equivalent O(11)ZrU3 tetrahedra, corners with four equivalent O(9)U4 tetrahedra,  an edgeedge with one O(11)ZrU3 tetrahedra,  an edgeedge with one O(13)ZrU3 tetrahedra, edges with two equivalent O(3)U4 tetrahedra, and edges with two equivalent O(7)Zr2U2 tetrahedra. In the fifth O site, O(5) is bonded to two equivalent U(1), one Zr(1), and one Zr(3) atom to form OZr2U2 tetrahedra that share  a cornercorner with one O(15)ZrU3 tetrahedra,  a cornercorner with one O(20)ZrU3 tetrahedra,  a cornercorner with one O(4)ZrU3 tetrahedra, corners with two equivalent O(9)U4 tetrahedra, corners with two equivalent O(18)Zr2U2 tetrahedra, corners with two equivalent O(5)Zr2U2 tetrahedra, corners with three equivalent O(13)ZrU3 tetrahedra, corners with four equivalent O(1)Zr2U2 tetrahedra,  an edgeedge with one O(2)Zr2U2 tetrahedra,  an edgeedge with one O(13)ZrU3 tetrahedra, edges with two equivalent O(6)Zr2U2 tetrahedra, and edges with two equivalent O(7)Zr2U2 tetrahedra. In the sixth O site, O(6) is bonded to one U(1), one U(7), and two equivalent Zr(3) atoms to form OZr2U2 tetrahedra that share  a cornercorner with one O(19)U4 tetrahedra,  a cornercorner with one O(9)U4 tetrahedra,  a cornercorner with one O(7)Zr2U2 tetrahedra, corners with two equivalent O(6)Zr2U2 tetrahedra, corners with two equivalent O(13)ZrU3 tetrahedra, corners with two equivalent O(15)ZrU3 tetrahedra, corners with three equivalent O(18)Zr2U2 tetrahedra, corners with four equivalent O(2)Zr2U2 tetrahedra,  an edgeedge with one O(1)Zr2U2 tetrahedra,  an edgeedge with one O(18)Zr2U2 tetrahedra, edges with two equivalent O(5)Zr2U2 tetrahedra, and edges with two equivalent O(20)ZrU3 tetrahedra. In the seventh O site, O(7) is bonded to one U(1), one U(2), and two equivalent Zr(1) atoms to form OZr2U2 tetrahedra that share  a cornercorner with one O(3)U4 tetrahedra,  a cornercorner with one O(12)Zr2U2 tetrahedra,  a cornercorner with one O(6)Zr2U2 tetrahedra, corners with two equivalent O(2)Zr2U2 tetrahedra, corners with two equivalent O(7)Zr2U2 tetrahedra, corners with two equivalent O(11)ZrU3 tetrahedra, corners with three equivalent O(1)Zr2U2 tetrahedra, corners with four equivalent O(13)ZrU3 tetrahedra,  an edgeedge with one O(9)U4 tetrahedra,  an edgeedge with one O(1)Zr2U2 tetrahedra, edges with two equivalent O(5)Zr2U2 tetrahedra, and edges with two equivalent O(4)ZrU3 tetrahedra. In the eighth O site, O(8) is bonded to one U(5), two equivalent U(3), and one Zr(2) atom to form OZrU3 tetrahedra that share  a cornercorner with one O(19)U4 tetrahedra,  a cornercorner with one O(18)Zr2U2 tetrahedra,  a cornercorner with one O(11)ZrU3 tetrahedra, corners with two equivalent O(3)U4 tetrahedra, corners with two equivalent O(15)ZrU3 tetrahedra, corners with two equivalent O(8)ZrU3 tetrahedra, corners with three equivalent O(17)ZrU3 tetrahedra, corners with four equivalent O(14)Zr2U2 tetrahedra,  an edgeedge with one O(16)ZrU3 tetrahedra,  an edgeedge with one O(17)ZrU3 tetrahedra, edges with two equivalent O(10)U4 tetrahedra, and edges with two equivalent O(12)Zr2U2 tetrahedra. In the ninth O site, O(9) is bonded to one U(1), one U(2), and two equivalent U(4) atoms to form OU4 tetrahedra that share  a cornercorner with one O(1)Zr2U2 tetrahedra,  a cornercorner with one O(12)Zr2U2 tetrahedra,  a cornercorner with one O(6)Zr2U2 tetrahedra, corners with two equivalent O(9)U4 tetrahedra, corners with two equivalent O(5)Zr2U2 tetrahedra, corners with two equivalent O(17)ZrU3 tetrahedra, corners with three equivalent O(3)U4 tetrahedra, corners with four equivalent O(4)ZrU3 tetrahedra,  an edgeedge with one O(3)U4 tetrahedra,  an edgeedge with one O(7)Zr2U2 tetrahedra, edges with two equivalent O(11)ZrU3 tetrahedra, and edges with two equivalent O(13)ZrU3 tetrahedra. In the tenth O site, O(10) is bonded to one U(3), one U(6), and two equivalent U(5) atoms to form OU4 tetrahedra that share  a cornercorner with one O(3)U4 tetrahedra,  a cornercorner with one O(12)Zr2U2 tetrahedra,  a cornercorner with one O(20)ZrU3 tetrahedra, corners with two equivalent O(10)U4 tetrahedra, corners with two equivalent O(18)Zr2U2 tetrahedra, corners with two equivalent O(17)ZrU3 tetrahedra, corners with three equivalent O(15)ZrU3 tetrahedra, corners with four equivalent O(16)ZrU3 tetrahedra,  an edgeedge with one O(14)Zr2U2 tetrahedra,  an edgeedge with one O(15)ZrU3 tetrahedra, edges with two equivalent O(19)U4 tetrahedra, and edges with two equivalent O(8)ZrU3 tetrahedra. In the eleventh O site, O(11) is bonded to one U(4), two equivalent U(2), and one Zr(2) atom to form OZrU3 tetrahedra that share  a cornercorner with one O(13)ZrU3 tetrahedra,  a cornercorner with one O(16)ZrU3 tetrahedra,  a cornercorner with one O(8)ZrU3 tetrahedra, corners with two equivalent O(14)Zr2U2 tetrahedra, corners with two equivalent O(7)Zr2U2 tetrahedra, corners with two equivalent O(11)ZrU3 tetrahedra, corners with three equivalent O(4)ZrU3 tetrahedra, corners with four equivalent O(3)U4 tetrahedra,  an edgeedge with one O(17)ZrU3 tetrahedra,  an edgeedge with one O(4)ZrU3 tetrahedra, edges with two equivalent O(9)U4 tetrahedra, and edges with two equivalent O(12)Zr2U2 tetrahedra. In the twelfth O site, O(12) is bonded to one U(2), one U(3), and two equivalent Zr(2) atoms to form OZr2U2 tetrahedra that share  a cornercorner with one O(10)U4 tetrahedra,  a cornercorner with one O(9)U4 tetrahedra,  a cornercorner with one O(7)Zr2U2 tetrahedra, corners with two equivalent O(12)Zr2U2 tetrahedra, corners with two equivalent O(16)ZrU3 tetrahedra, corners with two equivalent O(4)ZrU3 tetrahedra, corners with three equivalent O(14)Zr2U2 tetrahedra, corners with four equivalent O(17)ZrU3 tetrahedra,  an edgeedge with one O(3)U4 tetrahedra,  an edgeedge with one O(14)Zr2U2 tetrahedra, edges with two equivalent O(11)ZrU3 tetrahedra, and edges with two equivalent O(8)ZrU3 tetrahedra. In the thirteenth O site, O(13) is bonded to one U(4), two equivalent U(1), and one Zr(1) atom to form OZrU3 tetrahedra that share  a cornercorner with one O(2)Zr2U2 tetrahedra,  a cornercorner with one O(11)ZrU3 tetrahedra,  a cornercorner with one O(17)ZrU3 tetrahedra, corners with two equivalent O(3)U4 tetrahedra, corners with two equivalent O(6)Zr2U2 tetrahedra, corners with two equivalent O(13)ZrU3 tetrahedra, corners with three equivalent O(5)Zr2U2 tetrahedra, corners with four equivalent O(7)Zr2U2 tetrahedra,  an edgeedge with one O(5)Zr2U2 tetrahedra,  an edgeedge with one O(4)ZrU3 tetrahedra, edges with two equivalent O(9)U4 tetrahedra, and edges with two equivalent O(1)Zr2U2 tetrahedra. In the fourteenth O site, O(14) is bonded to one U(3), one U(6), and two equivalent Zr(2) atoms to form OZr2U2 tetrahedra that share  a cornercorner with one O(3)U4 tetrahedra,  a cornercorner with one O(15)ZrU3 tetrahedra,  a cornercorner with one O(20)ZrU3 tetrahedra, corners with two equivalent O(19)U4 tetrahedra, corners with two equivalent O(14)Zr2U2 tetrahedra, corners with two equivalent O(11)ZrU3 tetrahedra, corners with three equivalent O(12)Zr2U2 tetrahedra, corners with four equivalent O(8)ZrU3 tetrahedra,  an edgeedge with one O(10)U4 tetrahedra,  an edgeedge with one O(12)Zr2U2 tetrahedra, edges with two equivalent O(16)ZrU3 tetrahedra, and edges with two equivalent O(17)ZrU3 tetrahedra. In the fifteenth O site, O(15) is bonded to one U(6), two equivalent U(5), and one Zr(3) atom to form OZrU3 tetrahedra that share  a cornercorner with one O(14)Zr2U2 tetrahedra,  a cornercorner with one O(2)Zr2U2 tetrahedra,  a cornercorner with one O(5)Zr2U2 tetrahedra, corners with two equivalent O(6)Zr2U2 tetrahedra, corners with two equivalent O(15)ZrU3 tetrahedra, corners with two equivalent O(8)ZrU3 tetrahedra, corners with three equivalent O(10)U4 tetrahedra, corners with four equivalent O(19)U4 tetrahedra,  an edgeedge with one O(10)U4 tetrahedra,  an edgeedge with one O(20)ZrU3 tetrahedra, edges with two equivalent O(18)Zr2U2 tetrahedra, and edges with two equivalent O(16)ZrU3 tetrahedra. In the sixteenth O site, O(16) is bonded to one U(5), two equivalent U(6), and one Zr(2) atom to form OZrU3 tetrahedra that share  a cornercorner with one O(18)Zr2U2 tetrahedra,  a cornercorner with one O(11)ZrU3 tetrahedra,  a cornercorner with one O(17)ZrU3 tetrahedra, corners with two equivalent O(12)Zr2U2 tetrahedra, corners with two equivalent O(16)ZrU3 tetrahedra, corners with two equivalent O(20)ZrU3 tetrahedra, corners with three equivalent O(19)U4 tetrahedra, corners with four equivalent O(10)U4 tetrahedra,  an edgeedge with one O(19)U4 tetrahedra,  an edgeedge with one O(8)ZrU3 tetrahedra, edges with two equivalent O(14)Zr2U2 tetrahedra, and edges with two equivalent O(15)ZrU3 tetrahedra. In the seventeenth O site, O(17) is bonded to one U(4), two equivalent U(3), and one Zr(2) atom to form OZrU3 tetrahedra that share  a cornercorner with one O(13)ZrU3 tetrahedra,  a cornercorner with one O(16)ZrU3 tetrahedra,  a cornercorner with one O(4)ZrU3 tetrahedra, corners with two equivalent O(10)U4 tetrahedra, corners with two equivalent O(9)U4 tetrahedra, corners with two equivalent O(17)ZrU3 tetrahedra, corners with three equivalent O(8)ZrU3 tetrahedra, corners with four equivalent O(12)Zr2U2 tetrahedra,  an edgeedge with one O(11)ZrU3 tetrahedra,  an edgeedge with one O(8)ZrU3 tetrahedra, edges with two equivalent O(3)U4 tetrahedra, and edges with two equivalent O(14)Zr2U2 tetrahedra. In the eighteenth O site, O(18) is bonded to one U(5), one U(7), and two equivalent Zr(3) atoms to form OZr2U2 tetrahedra that share  a cornercorner with one O(1)Zr2U2 tetrahedra,  a cornercorner with one O(16)ZrU3 tetrahedra,  a cornercorner with one O(8)ZrU3 tetrahedra, corners with two equivalent O(10)U4 tetrahedra, corners with two equivalent O(18)Zr2U2 tetrahedra, corners with two equivalent O(5)Zr2U2 tetrahedra, corners with three equivalent O(6)Zr2U2 tetrahedra, corners with four equivalent O(20)ZrU3 tetrahedra,  an edgeedge with one O(19)U4 tetrahedra,  an edgeedge with one O(6)Zr2U2 tetrahedra, edges with two equivalent O(2)Zr2U2 tetrahedra, and edges with two equivalent O(15)ZrU3 tetrahedra. In the nineteenth O site, O(19) is bonded to one U(5), one U(7), and two equivalent U(6) atoms to form OU4 tetrahedra that share  a cornercorner with one O(1)Zr2U2 tetrahedra,  a cornercorner with one O(6)Zr2U2 tetrahedra,  a cornercorner with one O(8)ZrU3 tetrahedra, corners with two equivalent O(19)U4 tetrahedra, corners with two equivalent O(14)Zr2U2 tetrahedra, corners with two equivalent O(2)Zr2U2 tetrahedra, corners with three equivalent O(16)ZrU3 tetrahedra, corners with four equivalent O(15)ZrU3 tetrahedra,  an edgeedge with one O(18)Zr2U2 tetrahedra,  an edgeedge with one O(16)ZrU3 tetrahedra, edges with two equivalent O(10)U4 tetrahedra, and edges with two equivalent O(20)ZrU3 tetrahedra. In the twentieth O site, O(20) is bonded to one U(6), two equivalent U(7), and one Zr(3) atom to form OZrU3 tetrahedra that share  a cornercorner with one O(10)U4 tetrahedra,  a cornercorner with one O(14)Zr2U2 tetrahedra,  a cornercorner with one O(5)Zr2U2 tetrahedra, corners with two equivalent O(1)Zr2U2 tetrahedra, corners with two equivalent O(16)ZrU3 tetrahedra, corners with two equivalent O(20)ZrU3 tetrahedra, corners with three equivalent O(2)Zr2U2 tetrahedra, corners with four equivalent O(18)Zr2U2 tetrahedra,  an edgeedge with one O(2)Zr2U2 tetrahedra,  an edgeedge with one O(15)ZrU3 tetrahedra, edges with two equivalent O(19)U4 tetrahedra, and edges with two equivalent O(6)Zr2U2 tetrahedra.
U7Zr3O20 is Fluorite-derived structured and crystallizes in the monoclinic Cm space group. There are seven inequivalent U sites. In the first U site, U(1) is bonded in a body-centered cubic geometry to one O(1), one O(6), one O(7), one O(9), two equivalent O(13), and two equivalent O(5) atoms. The U(1)-O(1) bond length is 2.35 Å. The U(1)-O(6) bond length is 2.30 Å. The U(1)-O(7) bond length is 2.34 Å. The U(1)-O(9) bond length is 2.32 Å. Both U(1)-O(13) bond lengths are 2.33 Å. Both U(1)-O(5) bond lengths are 2.34 Å. In the second U site, U(2) is bonded in a body-centered cubic geometry to one O(12), one O(3), one O(7), one O(9), two equivalent O(11), and two equivalent O(4) atoms. The U(2)-O(12) bond length is 2.35 Å. The U(2)-O(3) bond length is 2.31 Å. The U(2)-O(7) bond length is 2.36 Å. The U(2)-O(9) bond length is 2.31 Å. Both U(2)-O(11) bond lengths are 2.34 Å. Both U(2)-O(4) bond lengths are 2.33 Å. In the third U site, U(3) is bonded in a body-centered cubic geometry to one O(10), one O(12), one O(14), one O(3), two equivalent O(17), and two equivalent O(8) atoms. The U(3)-O(10) bond length is 2.32 Å. The U(3)-O(12) bond length is 2.35 Å. The U(3)-O(14) bond length is 2.35 Å. The U(3)-O(3) bond length is 2.31 Å. Both U(3)-O(17) bond lengths are 2.33 Å. Both U(3)-O(8) bond lengths are 2.33 Å. In the fourth U site, U(4) is bonded in a body-centered cubic geometry to one O(11), one O(13), one O(17), one O(4), two equivalent O(3), and two equivalent O(9) atoms. The U(4)-O(11) bond length is 2.33 Å. The U(4)-O(13) bond length is 2.37 Å. The U(4)-O(17) bond length is 2.37 Å. The U(4)-O(4) bond length is 2.35 Å. Both U(4)-O(3) bond lengths are 2.33 Å. Both U(4)-O(9) bond lengths are 2.33 Å. In the fifth U site, U(5) is bonded in a body-centered cubic geometry to one O(16), one O(18), one O(19), one O(8), two equivalent O(10), and two equivalent O(15) atoms. The U(5)-O(16) bond length is 2.31 Å. The U(5)-O(18) bond length is 2.35 Å. The U(5)-O(19) bond length is 2.32 Å. The U(5)-O(8) bond length is 2.38 Å. Both U(5)-O(10) bond lengths are 2.32 Å. Both U(5)-O(15) bond lengths are 2.33 Å. In the sixth U site, U(6) is bonded in a body-centered cubic geometry to one O(10), one O(14), one O(15), one O(20), two equivalent O(16), and two equivalent O(19) atoms. The U(6)-O(10) bond length is 2.33 Å. The U(6)-O(14) bond length is 2.32 Å. The U(6)-O(15) bond length is 2.33 Å. The U(6)-O(20) bond length is 2.38 Å. Both U(6)-O(16) bond lengths are 2.34 Å. Both U(6)-O(19) bond lengths are 2.33 Å. In the seventh U site, U(7) is bonded in a body-centered cubic geometry to one O(1), one O(18), one O(19), one O(6), two equivalent O(2), and two equivalent O(20) atoms. The U(7)-O(1) bond length is 2.30 Å. The U(7)-O(18) bond length is 2.34 Å. The U(7)-O(19) bond length is 2.34 Å. The U(7)-O(6) bond length is 2.34 Å. Both U(7)-O(2) bond lengths are 2.34 Å. Both U(7)-O(20) bond lengths are 2.33 Å. There are three inequivalent Zr sites. In the first Zr site, Zr(1) is bonded in a body-centered cubic geometry to one O(13), one O(2), one O(4), one O(5), two equivalent O(1), and two equivalent O(7) atoms. The Zr(1)-O(13) bond length is 2.27 Å. The Zr(1)-O(2) bond length is 2.26 Å. The Zr(1)-O(4) bond length is 2.25 Å. The Zr(1)-O(5) bond length is 2.26 Å. Both Zr(1)-O(1) bond lengths are 2.29 Å. Both Zr(1)-O(7) bond lengths are 2.27 Å. In the second Zr site, Zr(2) is bonded in a body-centered cubic geometry to one O(11), one O(16), one O(17), one O(8), two equivalent O(12), and two equivalent O(14) atoms. The Zr(2)-O(11) bond length is 2.26 Å. The Zr(2)-O(16) bond length is 2.27 Å. The Zr(2)-O(17) bond length is 2.25 Å. The Zr(2)-O(8) bond length is 2.24 Å. Both Zr(2)-O(12) bond lengths are 2.28 Å. Both Zr(2)-O(14) bond lengths are 2.29 Å. In the third Zr site, Zr(3) is bonded in a body-centered cubic geometry to one O(15), one O(2), one O(20), one O(5), two equivalent O(18), and two equivalent O(6) atoms. The Zr(3)-O(15) bond length is 2.25 Å. The Zr(3)-O(2) bond length is 2.26 Å. The Zr(3)-O(20) bond length is 2.27 Å. The Zr(3)-O(5) bond length is 2.25 Å. Both Zr(3)-O(18) bond lengths are 2.28 Å. Both Zr(3)-O(6) bond lengths are 2.28 Å. There are twenty inequivalent O sites. In the first O site, O(1) is bonded to one U(1), one U(7), and two equivalent Zr(1) atoms to form OZr2U2 tetrahedra that share  a cornercorner with one O(19)U4 tetrahedra,  a cornercorner with one O(9)U4 tetrahedra,  a cornercorner with one O(18)Zr2U2 tetrahedra, corners with two equivalent O(1)Zr2U2 tetrahedra, corners with two equivalent O(20)ZrU3 tetrahedra, corners with two equivalent O(4)ZrU3 tetrahedra, corners with three equivalent O(7)Zr2U2 tetrahedra, corners with four equivalent O(5)Zr2U2 tetrahedra,  an edgeedge with one O(6)Zr2U2 tetrahedra,  an edgeedge with one O(7)Zr2U2 tetrahedra, edges with two equivalent O(2)Zr2U2 tetrahedra, and edges with two equivalent O(13)ZrU3 tetrahedra. In the second O site, O(2) is bonded to two equivalent U(7), one Zr(1), and one Zr(3) atom to form OZr2U2 tetrahedra that share  a cornercorner with one O(13)ZrU3 tetrahedra,  a cornercorner with one O(15)ZrU3 tetrahedra,  a cornercorner with one O(4)ZrU3 tetrahedra, corners with two equivalent O(19)U4 tetrahedra, corners with two equivalent O(2)Zr2U2 tetrahedra, corners with two equivalent O(7)Zr2U2 tetrahedra, corners with three equivalent O(20)ZrU3 tetrahedra, corners with four equivalent O(6)Zr2U2 tetrahedra,  an edgeedge with one O(5)Zr2U2 tetrahedra,  an edgeedge with one O(20)ZrU3 tetrahedra, edges with two equivalent O(1)Zr2U2 tetrahedra, and edges with two equivalent O(18)Zr2U2 tetrahedra. In the third O site, O(3) is bonded to one U(2), one U(3), and two equivalent U(4) atoms to form OU4 tetrahedra that share  a cornercorner with one O(10)U4 tetrahedra,  a cornercorner with one O(14)Zr2U2 tetrahedra,  a cornercorner with one O(7)Zr2U2 tetrahedra, corners with two equivalent O(3)U4 tetrahedra, corners with two equivalent O(13)ZrU3 tetrahedra, corners with two equivalent O(8)ZrU3 tetrahedra, corners with three equivalent O(9)U4 tetrahedra, corners with four equivalent O(11)ZrU3 tetrahedra,  an edgeedge with one O(9)U4 tetrahedra,  an edgeedge with one O(12)Zr2U2 tetrahedra, edges with two equivalent O(17)ZrU3 tetrahedra, and edges with two equivalent O(4)ZrU3 tetrahedra. In the fourth O site, O(4) is bonded to one U(4), two equivalent U(2), and one Zr(1) atom to form OZrU3 tetrahedra that share  a cornercorner with one O(2)Zr2U2 tetrahedra,  a cornercorner with one O(5)Zr2U2 tetrahedra,  a cornercorner with one O(17)ZrU3 tetrahedra, corners with two equivalent O(1)Zr2U2 tetrahedra, corners with two equivalent O(12)Zr2U2 tetrahedra, corners with two equivalent O(4)ZrU3 tetrahedra, corners with three equivalent O(11)ZrU3 tetrahedra, corners with four equivalent O(9)U4 tetrahedra,  an edgeedge with one O(11)ZrU3 tetrahedra,  an edgeedge with one O(13)ZrU3 tetrahedra, edges with two equivalent O(3)U4 tetrahedra, and edges with two equivalent O(7)Zr2U2 tetrahedra. In the fifth O site, O(5) is bonded to two equivalent U(1), one Zr(1), and one Zr(3) atom to form OZr2U2 tetrahedra that share  a cornercorner with one O(15)ZrU3 tetrahedra,  a cornercorner with one O(20)ZrU3 tetrahedra,  a cornercorner with one O(4)ZrU3 tetrahedra, corners with two equivalent O(9)U4 tetrahedra, corners with two equivalent O(18)Zr2U2 tetrahedra, corners with two equivalent O(5)Zr2U2 tetrahedra, corners with three equivalent O(13)ZrU3 tetrahedra, corners with four equivalent O(1)Zr2U2 tetrahedra,  an edgeedge with one O(2)Zr2U2 tetrahedra,  an edgeedge with one O(13)ZrU3 tetrahedra, edges with two equivalent O(6)Zr2U2 tetrahedra, and edges with two equivalent O(7)Zr2U2 tetrahedra. In the sixth O site, O(6) is bonded to one U(1), one U(7), and two equivalent Zr(3) atoms to form OZr2U2 tetrahedra that share  a cornercorner with one O(19)U4 tetrahedra,  a cornercorner with one O(9)U4 tetrahedra,  a cornercorner with one O(7)Zr2U2 tetrahedra, corners with two equivalent O(6)Zr2U2 tetrahedra, corners with two equivalent O(13)ZrU3 tetrahedra, corners with two equivalent O(15)ZrU3 tetrahedra, corners with three equivalent O(18)Zr2U2 tetrahedra, corners with four equivalent O(2)Zr2U2 tetrahedra,  an edgeedge with one O(1)Zr2U2 tetrahedra,  an edgeedge with one O(18)Zr2U2 tetrahedra, edges with two equivalent O(5)Zr2U2 tetrahedra, and edges with two equivalent O(20)ZrU3 tetrahedra. In the seventh O site, O(7) is bonded to one U(1), one U(2), and two equivalent Zr(1) atoms to form OZr2U2 tetrahedra that share  a cornercorner with one O(3)U4 tetrahedra,  a cornercorner with one O(12)Zr2U2 tetrahedra,  a cornercorner with one O(6)Zr2U2 tetrahedra, corners with two equivalent O(2)Zr2U2 tetrahedra, corners with two equivalent O(7)Zr2U2 tetrahedra, corners with two equivalent O(11)ZrU3 tetrahedra, corners with three equivalent O(1)Zr2U2 tetrahedra, corners with four equivalent O(13)ZrU3 tetrahedra,  an edgeedge with one O(9)U4 tetrahedra,  an edgeedge with one O(1)Zr2U2 tetrahedra, edges with two equivalent O(5)Zr2U2 tetrahedra, and edges with two equivalent O(4)ZrU3 tetrahedra. In the eighth O site, O(8) is bonded to one U(5), two equivalent U(3), and one Zr(2) atom to form OZrU3 tetrahedra that share  a cornercorner with one O(19)U4 tetrahedra,  a cornercorner with one O(18)Zr2U2 tetrahedra,  a cornercorner with one O(11)ZrU3 tetrahedra, corners with two equivalent O(3)U4 tetrahedra, corners with two equivalent O(15)ZrU3 tetrahedra, corners with two equivalent O(8)ZrU3 tetrahedra, corners with three equivalent O(17)ZrU3 tetrahedra, corners with four equivalent O(14)Zr2U2 tetrahedra,  an edgeedge with one O(16)ZrU3 tetrahedra,  an edgeedge with one O(17)ZrU3 tetrahedra, edges with two equivalent O(10)U4 tetrahedra, and edges with two equivalent O(12)Zr2U2 tetrahedra. In the ninth O site, O(9) is bonded to one U(1), one U(2), and two equivalent U(4) atoms to form OU4 tetrahedra that share  a cornercorner with one O(1)Zr2U2 tetrahedra,  a cornercorner with one O(12)Zr2U2 tetrahedra,  a cornercorner with one O(6)Zr2U2 tetrahedra, corners with two equivalent O(9)U4 tetrahedra, corners with two equivalent O(5)Zr2U2 tetrahedra, corners with two equivalent O(17)ZrU3 tetrahedra, corners with three equivalent O(3)U4 tetrahedra, corners with four equivalent O(4)ZrU3 tetrahedra,  an edgeedge with one O(3)U4 tetrahedra,  an edgeedge with one O(7)Zr2U2 tetrahedra, edges with two equivalent O(11)ZrU3 tetrahedra, and edges with two equivalent O(13)ZrU3 tetrahedra. In the tenth O site, O(10) is bonded to one U(3), one U(6), and two equivalent U(5) atoms to form OU4 tetrahedra that share  a cornercorner with one O(3)U4 tetrahedra,  a cornercorner with one O(12)Zr2U2 tetrahedra,  a cornercorner with one O(20)ZrU3 tetrahedra, corners with two equivalent O(10)U4 tetrahedra, corners with two equivalent O(18)Zr2U2 tetrahedra, corners with two equivalent O(17)ZrU3 tetrahedra, corners with three equivalent O(15)ZrU3 tetrahedra, corners with four equivalent O(16)ZrU3 tetrahedra,  an edgeedge with one O(14)Zr2U2 tetrahedra,  an edgeedge with one O(15)ZrU3 tetrahedra, edges with two equivalent O(19)U4 tetrahedra, and edges with two equivalent O(8)ZrU3 tetrahedra. In the eleventh O site, O(11) is bonded to one U(4), two equivalent U(2), and one Zr(2) atom to form OZrU3 tetrahedra that share  a cornercorner with one O(13)ZrU3 tetrahedra,  a cornercorner with one O(16)ZrU3 tetrahedra,  a cornercorner with one O(8)ZrU3 tetrahedra, corners with two equivalent O(14)Zr2U2 tetrahedra, corners with two equivalent O(7)Zr2U2 tetrahedra, corners with two equivalent O(11)ZrU3 tetrahedra, corners with three equivalent O(4)ZrU3 tetrahedra, corners with four equivalent O(3)U4 tetrahedra,  an edgeedge with one O(17)ZrU3 tetrahedra,  an edgeedge with one O(4)ZrU3 tetrahedra, edges with two equivalent O(9)U4 tetrahedra, and edges with two equivalent O(12)Zr2U2 tetrahedra. In the twelfth O site, O(12) is bonded to one U(2), one U(3), and two equivalent Zr(2) atoms to form OZr2U2 tetrahedra that share  a cornercorner with one O(10)U4 tetrahedra,  a cornercorner with one O(9)U4 tetrahedra,  a cornercorner with one O(7)Zr2U2 tetrahedra, corners with two equivalent O(12)Zr2U2 tetrahedra, corners with two equivalent O(16)ZrU3 tetrahedra, corners with two equivalent O(4)ZrU3 tetrahedra, corners with three equivalent O(14)Zr2U2 tetrahedra, corners with four equivalent O(17)ZrU3 tetrahedra,  an edgeedge with one O(3)U4 tetrahedra,  an edgeedge with one O(14)Zr2U2 tetrahedra, edges with two equivalent O(11)ZrU3 tetrahedra, and edges with two equivalent O(8)ZrU3 tetrahedra. In the thirteenth O site, O(13) is bonded to one U(4), two equivalent U(1), and one Zr(1) atom to form OZrU3 tetrahedra that share  a cornercorner with one O(2)Zr2U2 tetrahedra,  a cornercorner with one O(11)ZrU3 tetrahedra,  a cornercorner with one O(17)ZrU3 tetrahedra, corners with two equivalent O(3)U4 tetrahedra, corners with two equivalent O(6)Zr2U2 tetrahedra, corners with two equivalent O(13)ZrU3 tetrahedra, corners with three equivalent O(5)Zr2U2 tetrahedra, corners with four equivalent O(7)Zr2U2 tetrahedra,  an edgeedge with one O(5)Zr2U2 tetrahedra,  an edgeedge with one O(4)ZrU3 tetrahedra, edges with two equivalent O(9)U4 tetrahedra, and edges with two equivalent O(1)Zr2U2 tetrahedra. In the fourteenth O site, O(14) is bonded to one U(3), one U(6), and two equivalent Zr(2) atoms to form OZr2U2 tetrahedra that share  a cornercorner with one O(3)U4 tetrahedra,  a cornercorner with one O(15)ZrU3 tetrahedra,  a cornercorner with one O(20)ZrU3 tetrahedra, corners with two equivalent O(19)U4 tetrahedra, corners with two equivalent O(14)Zr2U2 tetrahedra, corners with two equivalent O(11)ZrU3 tetrahedra, corners with three equivalent O(12)Zr2U2 tetrahedra, corners with four equivalent O(8)ZrU3 tetrahedra,  an edgeedge with one O(10)U4 tetrahedra,  an edgeedge with one O(12)Zr2U2 tetrahedra, edges with two equivalent O(16)ZrU3 tetrahedra, and edges with two equivalent O(17)ZrU3 tetrahedra. In the fifteenth O site, O(15) is bonded to one U(6), two equivalent U(5), and one Zr(3) atom to form OZrU3 tetrahedra that share  a cornercorner with one O(14)Zr2U2 tetrahedra,  a cornercorner with one O(2)Zr2U2 tetrahedra,  a cornercorner with one O(5)Zr2U2 tetrahedra, corners with two equivalent O(6)Zr2U2 tetrahedra, corners with two equivalent O(15)ZrU3 tetrahedra, corners with two equivalent O(8)ZrU3 tetrahedra, corners with three equivalent O(10)U4 tetrahedra, corners with four equivalent O(19)U4 tetrahedra,  an edgeedge with one O(10)U4 tetrahedra,  an edgeedge with one O(20)ZrU3 tetrahedra, edges with two equivalent O(18)Zr2U2 tetrahedra, and edges with two equivalent O(16)ZrU3 tetrahedra. In the sixteenth O site, O(16) is bonded to one U(5), two equivalent U(6), and one Zr(2) atom to form OZrU3 tetrahedra that share  a cornercorner with one O(18)Zr2U2 tetrahedra,  a cornercorner with one O(11)ZrU3 tetrahedra,  a cornercorner with one O(17)ZrU3 tetrahedra, corners with two equivalent O(12)Zr2U2 tetrahedra, corners with two equivalent O(16)ZrU3 tetrahedra, corners with two equivalent O(20)ZrU3 tetrahedra, corners with three equivalent O(19)U4 tetrahedra, corners with four equivalent O(10)U4 tetrahedra,  an edgeedge with one O(19)U4 tetrahedra,  an edgeedge with one O(8)ZrU3 tetrahedra, edges with two equivalent O(14)Zr2U2 tetrahedra, and edges with two equivalent O(15)ZrU3 tetrahedra. In the seventeenth O site, O(17) is bonded to one U(4), two equivalent U(3), and one Zr(2) atom to form OZrU3 tetrahedra that share  a cornercorner with one O(13)ZrU3 tetrahedra,  a cornercorner with one O(16)ZrU3 tetrahedra,  a cornercorner with one O(4)ZrU3 tetrahedra, corners with two equivalent O(10)U4 tetrahedra, corners with two equivalent O(9)U4 tetrahedra, corners with two equivalent O(17)ZrU3 tetrahedra, corners with three equivalent O(8)ZrU3 tetrahedra, corners with four equivalent O(12)Zr2U2 tetrahedra,  an edgeedge with one O(11)ZrU3 tetrahedra,  an edgeedge with one O(8)ZrU3 tetrahedra, edges with two equivalent O(3)U4 tetrahedra, and edges with two equivalent O(14)Zr2U2 tetrahedra. In the eighteenth O site, O(18) is bonded to one U(5), one U(7), and two equivalent Zr(3) atoms to form OZr2U2 tetrahedra that share  a cornercorner with one O(1)Zr2U2 tetrahedra,  a cornercorner with one O(16)ZrU3 tetrahedra,  a cornercorner with one O(8)ZrU3 tetrahedra, corners with two equivalent O(10)U4 tetrahedra, corners with two equivalent O(18)Zr2U2 tetrahedra, corners with two equivalent O(5)Zr2U2 tetrahedra, corners with three equivalent O(6)Zr2U2 tetrahedra, corners with four equivalent O(20)ZrU3 tetrahedra,  an edgeedge with one O(19)U4 tetrahedra,  an edgeedge with one O(6)Zr2U2 tetrahedra, edges with two equivalent O(2)Zr2U2 tetrahedra, and edges with two equivalent O(15)ZrU3 tetrahedra. In the nineteenth O site, O(19) is bonded to one U(5), one U(7), and two equivalent U(6) atoms to form OU4 tetrahedra that share  a cornercorner with one O(1)Zr2U2 tetrahedra,  a cornercorner with one O(6)Zr2U2 tetrahedra,  a cornercorner with one O(8)ZrU3 tetrahedra, corners with two equivalent O(19)U4 tetrahedra, corners with two equivalent O(14)Zr2U2 tetrahedra, corners with two equivalent O(2)Zr2U2 tetrahedra, corners with three equivalent O(16)ZrU3 tetrahedra, corners with four equivalent O(15)ZrU3 tetrahedra,  an edgeedge with one O(18)Zr2U2 tetrahedra,  an edgeedge with one O(16)ZrU3 tetrahedra, edges with two equivalent O(10)U4 tetrahedra, and edges with two equivalent O(20)ZrU3 tetrahedra. In the twentieth O site, O(20) is bonded to one U(6), two equivalent U(7), and one Zr(3) atom to form OZrU3 tetrahedra that share  a cornercorner with one O(10)U4 tetrahedra,  a cornercorner with one O(14)Zr2U2 tetrahedra,  a cornercorner with one O(5)Zr2U2 tetrahedra, corners with two equivalent O(1)Zr2U2 tetrahedra, corners with two equivalent O(16)ZrU3 tetrahedra, corners with two equivalent O(20)ZrU3 tetrahedra, corners with three equivalent O(2)Zr2U2 tetrahedra, corners with four equivalent O(18)Zr2U2 tetrahedra,  an edgeedge with one O(2)Zr2U2 tetrahedra,  an edgeedge with one O(15)ZrU3 tetrahedra, edges with two equivalent O(19)U4 tetrahedra, and edges with two equivalent O(6)Zr2U2 tetrahedra.