U(BiO2)4 crystallizes in the orthorhombic Immm space group. U(1) is bonded in a body-centered cubic geometry to four equivalent O(3) and four equivalent O(4) atoms. There are two inequivalent Bi sites. In the first Bi site, Bi(1) is bonded in a 6-coordinate geometry to two equivalent O(1), two equivalent O(3), and two equivalent O(4) atoms. In the second Bi site, Bi(2) is bonded to two equivalent O(1) and four equivalent O(2) atoms to form a mixture of distorted edge and corner-sharing BiO6 octahedra. The corner-sharing octahedral tilt angles are 59°. There are four inequivalent O sites. In the first O site, O(1) is bonded to two equivalent Bi(1) and two equivalent Bi(2) atoms to form OBi4 tetrahedra that share corners with two equivalent O(3)U2Bi2 tetrahedra, corners with four equivalent O(1)Bi4 tetrahedra, corners with four equivalent O(4)U2Bi2 tetrahedra, corners with six equivalent O(2)Bi4 tetrahedra,  an edgeedge with one O(2)Bi4 tetrahedra, and  an edgeedge with one O(3)U2Bi2 tetrahedra. In the second O site, O(2) is bonded to four equivalent Bi(2) atoms to form a mixture of edge and corner-sharing OBi4 tetrahedra. In the third O site, O(3) is bonded to two equivalent U(1) and two equivalent Bi(1) atoms to form OU2Bi2 tetrahedra that share corners with two equivalent O(1)Bi4 tetrahedra, corners with four equivalent O(4)U2Bi2 tetrahedra, corners with six equivalent O(3)U2Bi2 tetrahedra,  an edgeedge with one O(1)Bi4 tetrahedra,  an edgeedge with one O(3)U2Bi2 tetrahedra, and edges with four equivalent O(4)U2Bi2 tetrahedra. In the fourth O site, O(4) is bonded to two equivalent U(1) and two equivalent Bi(1) atoms to form OU2Bi2 tetrahedra that share corners with four equivalent O(1)Bi4 tetrahedra, corners with four equivalent O(3)U2Bi2 tetrahedra, corners with six equivalent O(4)U2Bi2 tetrahedra,  an edgeedge with one O(4)U2Bi2 tetrahedra, and edges with four equivalent O(3)U2Bi2 tetrahedra.
U(BiO2)4 crystallizes in the orthorhombic Immm space group. U(1) is bonded in a body-centered cubic geometry to four equivalent O(3) and four equivalent O(4) atoms. All U(1)-O(3) bond lengths are 2.30 Å. All U(1)-O(4) bond lengths are 2.41 Å. There are two inequivalent Bi sites. In the first Bi site, Bi(1) is bonded in a 6-coordinate geometry to two equivalent O(1), two equivalent O(3), and two equivalent O(4) atoms. Both Bi(1)-O(1) bond lengths are 2.47 Å. Both Bi(1)-O(3) bond lengths are 2.44 Å. Both Bi(1)-O(4) bond lengths are 2.34 Å. In the second Bi site, Bi(2) is bonded to two equivalent O(1) and four equivalent O(2) atoms to form a mixture of distorted edge and corner-sharing BiO6 octahedra. The corner-sharing octahedral tilt angles are 59°. Both Bi(2)-O(1) bond lengths are 2.50 Å. There are two shorter (2.28 Å) and two longer (2.42 Å) Bi(2)-O(2) bond lengths. There are four inequivalent O sites. In the first O site, O(1) is bonded to two equivalent Bi(1) and two equivalent Bi(2) atoms to form OBi4 tetrahedra that share corners with two equivalent O(3)U2Bi2 tetrahedra, corners with four equivalent O(1)Bi4 tetrahedra, corners with four equivalent O(4)U2Bi2 tetrahedra, corners with six equivalent O(2)Bi4 tetrahedra,  an edgeedge with one O(2)Bi4 tetrahedra, and  an edgeedge with one O(3)U2Bi2 tetrahedra. In the second O site, O(2) is bonded to four equivalent Bi(2) atoms to form a mixture of edge and corner-sharing OBi4 tetrahedra. In the third O site, O(3) is bonded to two equivalent U(1) and two equivalent Bi(1) atoms to form OU2Bi2 tetrahedra that share corners with two equivalent O(1)Bi4 tetrahedra, corners with four equivalent O(4)U2Bi2 tetrahedra, corners with six equivalent O(3)U2Bi2 tetrahedra,  an edgeedge with one O(1)Bi4 tetrahedra,  an edgeedge with one O(3)U2Bi2 tetrahedra, and edges with four equivalent O(4)U2Bi2 tetrahedra. In the fourth O site, O(4) is bonded to two equivalent U(1) and two equivalent Bi(1) atoms to form OU2Bi2 tetrahedra that share corners with four equivalent O(1)Bi4 tetrahedra, corners with four equivalent O(3)U2Bi2 tetrahedra, corners with six equivalent O(4)U2Bi2 tetrahedra,  an edgeedge with one O(4)U2Bi2 tetrahedra, and edges with four equivalent O(3)U2Bi2 tetrahedra.