U6O11 crystallizes in the monoclinic Cm space group. There are four inequivalent U sites. In the first U site, U(1) is bonded in a body-centered cubic geometry to one O(2), one O(3), one O(4), one O(7), two equivalent O(1), and two equivalent O(5) atoms. In the second U site, U(2) is bonded in a 7-coordinate geometry to one O(1), one O(5), one O(6), two equivalent O(2), and two equivalent O(4) atoms. In the third U site, U(3) is bonded in a 7-coordinate geometry to one O(3), one O(6), one O(7), two equivalent O(2), and two equivalent O(4) atoms. In the fourth U site, U(4) is bonded in a 7-coordinate geometry to one O(3), one O(6), one O(7), two equivalent O(1), and two equivalent O(5) atoms. There are seven inequivalent O sites. In the first O site, O(1) is bonded to one U(2), one U(4), and two equivalent U(1) atoms to form a mixture of corner and edge-sharing OU4 tetrahedra. In the second O site, O(2) is bonded to one U(1), one U(3), and two equivalent U(2) atoms to form a mixture of corner and edge-sharing OU4 tetrahedra. In the third O site, O(3) is bonded to one U(3), one U(4), and two equivalent U(1) atoms to form a mixture of corner and edge-sharing OU4 tetrahedra. In the fourth O site, O(4) is bonded to one U(1), one U(3), and two equivalent U(2) atoms to form a mixture of corner and edge-sharing OU4 tetrahedra. In the fifth O site, O(5) is bonded to one U(2), one U(4), and two equivalent U(1) atoms to form a mixture of corner and edge-sharing OU4 tetrahedra. In the sixth O site, O(6) is bonded to one U(3), one U(4), and two equivalent U(2) atoms to form a mixture of corner and edge-sharing OU4 tetrahedra. In the seventh O site, O(7) is bonded to one U(3), one U(4), and two equivalent U(1) atoms to form a mixture of corner and edge-sharing OU4 tetrahedra.
U6O11 crystallizes in the monoclinic Cm space group. There are four inequivalent U sites. In the first U site, U(1) is bonded in a body-centered cubic geometry to one O(2), one O(3), one O(4), one O(7), two equivalent O(1), and two equivalent O(5) atoms. The U(1)-O(2) bond length is 2.45 Å. The U(1)-O(3) bond length is 2.42 Å. The U(1)-O(4) bond length is 2.34 Å. The U(1)-O(7) bond length is 2.35 Å. There is one shorter (2.32 Å) and one longer (2.36 Å) U(1)-O(1) bond length. Both U(1)-O(5) bond lengths are 2.43 Å. In the second U site, U(2) is bonded in a 7-coordinate geometry to one O(1), one O(5), one O(6), two equivalent O(2), and two equivalent O(4) atoms. The U(2)-O(1) bond length is 2.34 Å. The U(2)-O(5) bond length is 2.32 Å. The U(2)-O(6) bond length is 2.36 Å. There is one shorter (2.31 Å) and one longer (2.33 Å) U(2)-O(2) bond length. There is one shorter (2.31 Å) and one longer (2.32 Å) U(2)-O(4) bond length. In the third U site, U(3) is bonded in a 7-coordinate geometry to one O(3), one O(6), one O(7), two equivalent O(2), and two equivalent O(4) atoms. The U(3)-O(3) bond length is 2.33 Å. The U(3)-O(6) bond length is 2.33 Å. The U(3)-O(7) bond length is 2.33 Å. Both U(3)-O(2) bond lengths are 2.33 Å. Both U(3)-O(4) bond lengths are 2.32 Å. In the fourth U site, U(4) is bonded in a 7-coordinate geometry to one O(3), one O(6), one O(7), two equivalent O(1), and two equivalent O(5) atoms. The U(4)-O(3) bond length is 2.31 Å. The U(4)-O(6) bond length is 2.32 Å. The U(4)-O(7) bond length is 2.34 Å. Both U(4)-O(1) bond lengths are 2.37 Å. Both U(4)-O(5) bond lengths are 2.33 Å. There are seven inequivalent O sites. In the first O site, O(1) is bonded to one U(2), one U(4), and two equivalent U(1) atoms to form a mixture of corner and edge-sharing OU4 tetrahedra. In the second O site, O(2) is bonded to one U(1), one U(3), and two equivalent U(2) atoms to form a mixture of corner and edge-sharing OU4 tetrahedra. In the third O site, O(3) is bonded to one U(3), one U(4), and two equivalent U(1) atoms to form a mixture of corner and edge-sharing OU4 tetrahedra. In the fourth O site, O(4) is bonded to one U(1), one U(3), and two equivalent U(2) atoms to form a mixture of corner and edge-sharing OU4 tetrahedra. In the fifth O site, O(5) is bonded to one U(2), one U(4), and two equivalent U(1) atoms to form a mixture of corner and edge-sharing OU4 tetrahedra. In the sixth O site, O(6) is bonded to one U(3), one U(4), and two equivalent U(2) atoms to form a mixture of corner and edge-sharing OU4 tetrahedra. In the seventh O site, O(7) is bonded to one U(3), one U(4), and two equivalent U(1) atoms to form a mixture of corner and edge-sharing OU4 tetrahedra.