U3La2O11 crystallizes in the orthorhombic Immm space group. There are two inequivalent U sites. In the first U site, U(1) is bonded in a 10-coordinate geometry to two equivalent O(2), two equivalent O(3), two equivalent O(4), and four equivalent O(1) atoms. In the second U site, U(2) is bonded in a body-centered cubic geometry to two equivalent O(4), four equivalent O(1), and four equivalent O(2) atoms. La(1) is bonded in a body-centered cubic geometry to two equivalent O(1) and six equivalent O(3) atoms. There are four inequivalent O sites. In the first O site, O(1) is bonded to one U(2), two equivalent U(1), and one La(1) atom to form OLaU3 tetrahedra that share corners with three equivalent O(4)U6 octahedra, corners with four equivalent O(2)U4 tetrahedra, corners with six equivalent O(3)La3U tetrahedra, corners with six equivalent O(1)LaU3 tetrahedra, edges with two equivalent O(3)La3U tetrahedra, edges with two equivalent O(1)LaU3 tetrahedra, edges with two equivalent O(2)U4 tetrahedra, and  a faceface with one O(4)U6 octahedra. The corner-sharing octahedral tilt angles are 54°. In the second O site, O(2) is bonded to two equivalent U(1) and two equivalent U(2) atoms to form OU4 tetrahedra that share corners with two equivalent O(4)U6 octahedra, corners with four equivalent O(3)La3U tetrahedra, corners with four equivalent O(2)U4 tetrahedra, corners with eight equivalent O(1)LaU3 tetrahedra, edges with two equivalent O(2)U4 tetrahedra, edges with four equivalent O(1)LaU3 tetrahedra, and faces with two equivalent O(4)U6 octahedra. The corner-sharing octahedral tilt angles are 58°. In the third O site, O(3) is bonded to one U(1) and three equivalent La(1) atoms to form OLa3U tetrahedra that share corners with two equivalent O(4)U6 octahedra, corners with two equivalent O(2)U4 tetrahedra, corners with six equivalent O(1)LaU3 tetrahedra, corners with eight equivalent O(3)La3U tetrahedra, edges with two equivalent O(1)LaU3 tetrahedra, and edges with four equivalent O(3)La3U tetrahedra. The corner-sharing octahedral tilt angles are 56°. In the fourth O site, O(4) is bonded to two equivalent U(2) and four equivalent U(1) atoms to form distorted OU6 octahedra that share corners with two equivalent O(4)U6 octahedra, corners with four equivalent O(2)U4 tetrahedra, corners with eight equivalent O(3)La3U tetrahedra, corners with twelve equivalent O(1)LaU3 tetrahedra, edges with two equivalent O(4)U6 octahedra, faces with four equivalent O(1)LaU3 tetrahedra, and faces with four equivalent O(2)U4 tetrahedra. The corner-sharing octahedra are not tilted.
U3La2O11 crystallizes in the orthorhombic Immm space group. There are two inequivalent U sites. In the first U site, U(1) is bonded in a 10-coordinate geometry to two equivalent O(2), two equivalent O(3), two equivalent O(4), and four equivalent O(1) atoms. Both U(1)-O(2) bond lengths are 2.40 Å. Both U(1)-O(3) bond lengths are 2.18 Å. Both U(1)-O(4) bond lengths are 2.64 Å. All U(1)-O(1) bond lengths are 2.44 Å. In the second U site, U(2) is bonded in a body-centered cubic geometry to two equivalent O(4), four equivalent O(1), and four equivalent O(2) atoms. Both U(2)-O(4) bond lengths are 2.80 Å. All U(2)-O(1) bond lengths are 2.25 Å. All U(2)-O(2) bond lengths are 2.28 Å. La(1) is bonded in a body-centered cubic geometry to two equivalent O(1) and six equivalent O(3) atoms. Both La(1)-O(1) bond lengths are 2.40 Å. There are four shorter (2.48 Å) and two longer (2.54 Å) La(1)-O(3) bond lengths. There are four inequivalent O sites. In the first O site, O(1) is bonded to one U(2), two equivalent U(1), and one La(1) atom to form OLaU3 tetrahedra that share corners with three equivalent O(4)U6 octahedra, corners with four equivalent O(2)U4 tetrahedra, corners with six equivalent O(3)La3U tetrahedra, corners with six equivalent O(1)LaU3 tetrahedra, edges with two equivalent O(3)La3U tetrahedra, edges with two equivalent O(1)LaU3 tetrahedra, edges with two equivalent O(2)U4 tetrahedra, and  a faceface with one O(4)U6 octahedra. The corner-sharing octahedral tilt angles are 54°. In the second O site, O(2) is bonded to two equivalent U(1) and two equivalent U(2) atoms to form OU4 tetrahedra that share corners with two equivalent O(4)U6 octahedra, corners with four equivalent O(3)La3U tetrahedra, corners with four equivalent O(2)U4 tetrahedra, corners with eight equivalent O(1)LaU3 tetrahedra, edges with two equivalent O(2)U4 tetrahedra, edges with four equivalent O(1)LaU3 tetrahedra, and faces with two equivalent O(4)U6 octahedra. The corner-sharing octahedral tilt angles are 58°. In the third O site, O(3) is bonded to one U(1) and three equivalent La(1) atoms to form OLa3U tetrahedra that share corners with two equivalent O(4)U6 octahedra, corners with two equivalent O(2)U4 tetrahedra, corners with six equivalent O(1)LaU3 tetrahedra, corners with eight equivalent O(3)La3U tetrahedra, edges with two equivalent O(1)LaU3 tetrahedra, and edges with four equivalent O(3)La3U tetrahedra. The corner-sharing octahedral tilt angles are 56°. In the fourth O site, O(4) is bonded to two equivalent U(2) and four equivalent U(1) atoms to form distorted OU6 octahedra that share corners with two equivalent O(4)U6 octahedra, corners with four equivalent O(2)U4 tetrahedra, corners with eight equivalent O(3)La3U tetrahedra, corners with twelve equivalent O(1)LaU3 tetrahedra, edges with two equivalent O(4)U6 octahedra, faces with four equivalent O(1)LaU3 tetrahedra, and faces with four equivalent O(2)U4 tetrahedra. The corner-sharing octahedra are not tilted.