U3O11 crystallizes in the orthorhombic Immm space group. There are two inequivalent U sites. In the first U site, U(1) is bonded to one O(2), one O(3), one O(4), and four equivalent O(1) atoms to form distorted UO7 pentagonal bipyramids that share  a cornercorner with one U(1)O7 pentagonal bipyramid, corners with two equivalent U(2)O6 square pyramids, edges with two equivalent U(1)O7 pentagonal bipyramids, and  an edgeedge with one U(2)O6 square pyramid. In the second U site, U(2) is bonded to one O(5), one O(6), and four equivalent O(1) atoms to form a mixture of distorted corner and edge-sharing UO6 square pyramids. There are six inequivalent O sites. In the first O site, O(6) is bonded in a linear geometry to one U(2) and one O(6) atom. In the second O site, O(1) is bonded in a 3-coordinate geometry to one U(2) and two equivalent U(1) atoms. In the third O site, O(2) is bonded in a bent 150 degrees geometry to two equivalent U(1) atoms. In the fourth O site, O(3) is bonded in a single-bond geometry to one U(1) atom. In the fifth O site, O(4) is bonded in a single-bond geometry to one U(1) atom. In the sixth O site, O(5) is bonded in a single-bond geometry to one U(2) atom.
U3O11 crystallizes in the orthorhombic Immm space group. There are two inequivalent U sites. In the first U site, U(1) is bonded to one O(2), one O(3), one O(4), and four equivalent O(1) atoms to form distorted UO7 pentagonal bipyramids that share  a cornercorner with one U(1)O7 pentagonal bipyramid, corners with two equivalent U(2)O6 square pyramids, edges with two equivalent U(1)O7 pentagonal bipyramids, and  an edgeedge with one U(2)O6 square pyramid. The U(1)-O(2) bond length is 2.13 Å. The U(1)-O(3) bond length is 1.81 Å. The U(1)-O(4) bond length is 1.80 Å. There are two shorter (2.38 Å) and two longer (2.48 Å) U(1)-O(1) bond lengths. In the second U site, U(2) is bonded to one O(5), one O(6), and four equivalent O(1) atoms to form a mixture of distorted corner and edge-sharing UO6 square pyramids. The U(2)-O(5) bond length is 1.87 Å. The U(2)-O(6) bond length is 2.93 Å. All U(2)-O(1) bond lengths are 2.06 Å. There are six inequivalent O sites. In the first O site, O(6) is bonded in a linear geometry to one U(2) and one O(6) atom. The O(6)-O(6) bond length is 1.23 Å. In the second O site, O(1) is bonded in a 3-coordinate geometry to one U(2) and two equivalent U(1) atoms. In the third O site, O(2) is bonded in a bent 150 degrees geometry to two equivalent U(1) atoms. In the fourth O site, O(3) is bonded in a single-bond geometry to one U(1) atom. In the fifth O site, O(4) is bonded in a single-bond geometry to one U(1) atom. In the sixth O site, O(5) is bonded in a single-bond geometry to one U(2) atom.