U7(Se6O)2 crystallizes in the hexagonal P-6 space group. There are three inequivalent U sites. In the first U site, U(1) is bonded in a distorted single-bond geometry to one Se(2), one Se(3), two equivalent Se(1), four equivalent Se(4), and one O(1) atom. In the second U site, U(2) is bonded in a distorted single-bond geometry to one Se(1), one Se(4), two equivalent Se(2), four equivalent Se(3), and one O(2) atom. In the third U site, U(3) is bonded in a 9-coordinate geometry to three equivalent Se(1) and six equivalent Se(2) atoms. There are four inequivalent Se sites. In the first Se site, Se(1) is bonded to one U(2), one U(3), and two equivalent U(1) atoms to form SeU4 tetrahedra that share corners with four equivalent Se(1)U4 tetrahedra, corners with two equivalent Se(2)U5 trigonal bipyramids, and edges with four equivalent Se(2)U5 trigonal bipyramids. In the second Se site, Se(2) is bonded to one U(1), two equivalent U(2), and two equivalent U(3) atoms to form distorted SeU5 trigonal bipyramids that share corners with two equivalent Se(1)U4 tetrahedra, corners with four equivalent Se(2)U5 trigonal bipyramids, edges with four equivalent Se(1)U4 tetrahedra, and edges with four equivalent Se(2)U5 trigonal bipyramids. In the third Se site, Se(3) is bonded in a 5-coordinate geometry to one U(1) and four equivalent U(2) atoms. In the fourth Se site, Se(4) is bonded in a 5-coordinate geometry to one U(2) and four equivalent U(1) atoms. There are two inequivalent O sites. In the first O site, O(1) is bonded in a trigonal planar geometry to three equivalent U(1) atoms. In the second O site, O(2) is bonded in a trigonal planar geometry to three equivalent U(2) atoms.
U7(Se6O)2 crystallizes in the hexagonal P-6 space group. There are three inequivalent U sites. In the first U site, U(1) is bonded in a distorted single-bond geometry to one Se(2), one Se(3), two equivalent Se(1), four equivalent Se(4), and one O(1) atom. The U(1)-Se(2) bond length is 3.13 Å. The U(1)-Se(3) bond length is 3.00 Å. Both U(1)-Se(1) bond lengths are 2.88 Å. There are two shorter (2.98 Å) and two longer (3.06 Å) U(1)-Se(4) bond lengths. The U(1)-O(1) bond length is 2.19 Å. In the second U site, U(2) is bonded in a distorted single-bond geometry to one Se(1), one Se(4), two equivalent Se(2), four equivalent Se(3), and one O(2) atom. The U(2)-Se(1) bond length is 2.93 Å. The U(2)-Se(4) bond length is 3.00 Å. Both U(2)-Se(2) bond lengths are 3.11 Å. There are two shorter (3.00 Å) and two longer (3.03 Å) U(2)-Se(3) bond lengths. The U(2)-O(2) bond length is 2.22 Å. In the third U site, U(3) is bonded in a 9-coordinate geometry to three equivalent Se(1) and six equivalent Se(2) atoms. All U(3)-Se(1) bond lengths are 2.88 Å. All U(3)-Se(2) bond lengths are 3.16 Å. There are four inequivalent Se sites. In the first Se site, Se(1) is bonded to one U(2), one U(3), and two equivalent U(1) atoms to form SeU4 tetrahedra that share corners with four equivalent Se(1)U4 tetrahedra, corners with two equivalent Se(2)U5 trigonal bipyramids, and edges with four equivalent Se(2)U5 trigonal bipyramids. In the second Se site, Se(2) is bonded to one U(1), two equivalent U(2), and two equivalent U(3) atoms to form distorted SeU5 trigonal bipyramids that share corners with two equivalent Se(1)U4 tetrahedra, corners with four equivalent Se(2)U5 trigonal bipyramids, edges with four equivalent Se(1)U4 tetrahedra, and edges with four equivalent Se(2)U5 trigonal bipyramids. In the third Se site, Se(3) is bonded in a 5-coordinate geometry to one U(1) and four equivalent U(2) atoms. In the fourth Se site, Se(4) is bonded in a 5-coordinate geometry to one U(2) and four equivalent U(1) atoms. There are two inequivalent O sites. In the first O site, O(1) is bonded in a trigonal planar geometry to three equivalent U(1) atoms. In the second O site, O(2) is bonded in a trigonal planar geometry to three equivalent U(2) atoms.