U2O5 crystallizes in the monoclinic C2/m space group. There are three inequivalent U sites. In the first U site, U(1) is bonded in a body-centered cubic geometry to one O(3), one O(7), three equivalent O(5), and three equivalent O(6) atoms. In the second U site, U(2) is bonded in a 11-coordinate geometry to one O(5), three equivalent O(1), three equivalent O(3), and four equivalent O(2) atoms. In the third U site, U(3) is bonded in a 11-coordinate geometry to one O(6), three equivalent O(7), three equivalent O(8), and four equivalent O(4) atoms. There are eight inequivalent O sites. In the first O site, O(1) is bonded in a trigonal planar geometry to three equivalent U(2) atoms. In the second O site, O(2) is bonded to four equivalent U(2) atoms to form a mixture of edge and corner-sharing OU4 tetrahedra. In the third O site, O(3) is bonded in a single-bond geometry to one U(1) and three equivalent U(2) atoms. In the fourth O site, O(4) is bonded to four equivalent U(3) atoms to form OU4 trigonal pyramids that share corners with three equivalent O(8)U6 octahedra, corners with four equivalent O(6)U4 tetrahedra, corners with six equivalent O(7)U4 tetrahedra, corners with six equivalent O(4)U4 trigonal pyramids, edges with three equivalent O(7)U4 tetrahedra, edges with three equivalent O(4)U4 trigonal pyramids, and faces with three equivalent O(8)U6 octahedra. The corner-sharing octahedral tilt angles range from 40-41°. In the fifth O site, O(5) is bonded in a distorted trigonal non-coplanar geometry to one U(2) and three equivalent U(1) atoms. In the sixth O site, O(6) is bonded to one U(3) and three equivalent U(1) atoms to form OU4 tetrahedra that share corners with three equivalent O(8)U6 octahedra, corners with six equivalent O(6)U4 tetrahedra, corners with four equivalent O(4)U4 trigonal pyramids, and edges with three equivalent O(7)U4 tetrahedra. The corner-sharing octahedral tilt angles range from 57-58°. In the seventh O site, O(7) is bonded to one U(1) and three equivalent U(3) atoms to form distorted OU4 tetrahedra that share corners with six equivalent O(8)U6 octahedra, corners with six equivalent O(7)U4 tetrahedra, corners with six equivalent O(4)U4 trigonal pyramids, edges with three equivalent O(6)U4 tetrahedra, edges with three equivalent O(4)U4 trigonal pyramids, and  a faceface with one O(8)U6 octahedra. The corner-sharing octahedral tilt angles range from 51-52°. In the eighth O site, O(8) is bonded to six equivalent U(3) atoms to form OU6 octahedra that share corners with six equivalent O(6)U4 tetrahedra, corners with twelve equivalent O(7)U4 tetrahedra, corners with six equivalent O(4)U4 trigonal pyramids, edges with six equivalent O(8)U6 octahedra, faces with two equivalent O(7)U4 tetrahedra, and faces with six equivalent O(4)U4 trigonal pyramids.
U2O5 crystallizes in the monoclinic C2/m space group. There are three inequivalent U sites. In the first U site, U(1) is bonded in a body-centered cubic geometry to one O(3), one O(7), three equivalent O(5), and three equivalent O(6) atoms. The U(1)-O(3) bond length is 1.94 Å. The U(1)-O(7) bond length is 2.09 Å. There is one shorter (2.26 Å) and two longer (2.31 Å) U(1)-O(5) bond lengths. There is one shorter (2.33 Å) and two longer (2.36 Å) U(1)-O(6) bond lengths. In the second U site, U(2) is bonded in a 11-coordinate geometry to one O(5), three equivalent O(1), three equivalent O(3), and four equivalent O(2) atoms. The U(2)-O(5) bond length is 2.95 Å. There is one shorter (2.23 Å) and two longer (2.25 Å) U(2)-O(1) bond lengths. There is one shorter (2.66 Å) and two longer (2.75 Å) U(2)-O(3) bond lengths. There are a spread of U(2)-O(2) bond distances ranging from 2.14-2.43 Å. In the third U site, U(3) is bonded in a 11-coordinate geometry to one O(6), three equivalent O(7), three equivalent O(8), and four equivalent O(4) atoms. The U(3)-O(6) bond length is 2.46 Å. All U(3)-O(7) bond lengths are 2.50 Å. There is one shorter (2.59 Å) and two longer (2.64 Å) U(3)-O(8) bond lengths. There are a spread of U(3)-O(4) bond distances ranging from 2.24-2.43 Å. There are eight inequivalent O sites. In the first O site, O(1) is bonded in a trigonal planar geometry to three equivalent U(2) atoms. In the second O site, O(2) is bonded to four equivalent U(2) atoms to form a mixture of edge and corner-sharing OU4 tetrahedra. In the third O site, O(3) is bonded in a single-bond geometry to one U(1) and three equivalent U(2) atoms. In the fourth O site, O(4) is bonded to four equivalent U(3) atoms to form OU4 trigonal pyramids that share corners with three equivalent O(8)U6 octahedra, corners with four equivalent O(6)U4 tetrahedra, corners with six equivalent O(7)U4 tetrahedra, corners with six equivalent O(4)U4 trigonal pyramids, edges with three equivalent O(7)U4 tetrahedra, edges with three equivalent O(4)U4 trigonal pyramids, and faces with three equivalent O(8)U6 octahedra. The corner-sharing octahedral tilt angles range from 40-41°. In the fifth O site, O(5) is bonded in a distorted trigonal non-coplanar geometry to one U(2) and three equivalent U(1) atoms. In the sixth O site, O(6) is bonded to one U(3) and three equivalent U(1) atoms to form OU4 tetrahedra that share corners with three equivalent O(8)U6 octahedra, corners with six equivalent O(6)U4 tetrahedra, corners with four equivalent O(4)U4 trigonal pyramids, and edges with three equivalent O(7)U4 tetrahedra. The corner-sharing octahedral tilt angles range from 57-58°. In the seventh O site, O(7) is bonded to one U(1) and three equivalent U(3) atoms to form distorted OU4 tetrahedra that share corners with six equivalent O(8)U6 octahedra, corners with six equivalent O(7)U4 tetrahedra, corners with six equivalent O(4)U4 trigonal pyramids, edges with three equivalent O(6)U4 tetrahedra, edges with three equivalent O(4)U4 trigonal pyramids, and  a faceface with one O(8)U6 octahedra. The corner-sharing octahedral tilt angles range from 51-52°. In the eighth O site, O(8) is bonded to six equivalent U(3) atoms to form OU6 octahedra that share corners with six equivalent O(6)U4 tetrahedra, corners with twelve equivalent O(7)U4 tetrahedra, corners with six equivalent O(4)U4 trigonal pyramids, edges with six equivalent O(8)U6 octahedra, faces with two equivalent O(7)U4 tetrahedra, and faces with six equivalent O(4)U4 trigonal pyramids.