K2U3(TeO7)2 crystallizes in the triclinic P-1 space group. K(1) is bonded to one O(3), one O(7), two equivalent O(1), and two equivalent O(2) atoms to form distorted KO6 octahedra that share corners with two equivalent U(2)O6 octahedra, corners with four equivalent U(1)O7 pentagonal bipyramids, and edges with two equivalent K(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 53-59°. There are two inequivalent U sites. In the first U site, U(1) is bonded to one O(2), one O(3), one O(5), one O(6), one O(7), and two equivalent O(4) atoms to form distorted UO7 pentagonal bipyramids that share  a cornercorner with one U(2)O6 octahedra, corners with four equivalent K(1)O6 octahedra,  an edgeedge with one U(2)O6 octahedra, and  an edgeedge with one U(1)O7 pentagonal bipyramid. The corner-sharing octahedral tilt angles range from 47-64°. In the second U site, U(2) is bonded to two equivalent O(1), two equivalent O(4), and two equivalent O(5) atoms to form distorted UO6 octahedra that share corners with four equivalent K(1)O6 octahedra, corners with two equivalent U(1)O7 pentagonal bipyramids, and edges with two equivalent U(1)O7 pentagonal bipyramids. The corner-sharing octahedral tilt angles range from 53-59°. Te(1) is bonded in a 3-coordinate geometry to one O(5), one O(6), and two equivalent O(7) atoms. There are seven inequivalent O sites. In the first O site, O(1) is bonded in a distorted single-bond geometry to two equivalent K(1) and one U(2) atom. In the second O site, O(2) is bonded in a distorted single-bond geometry to two equivalent K(1) and one U(1) atom. In the third O site, O(3) is bonded in a distorted bent 120 degrees geometry to one K(1) and one U(1) atom. In the fourth O site, O(4) is bonded in a distorted trigonal planar geometry to one U(2) and two equivalent U(1) atoms. In the fifth O site, O(5) is bonded in a trigonal planar geometry to one U(1), one U(2), and one Te(1) atom. In the sixth O site, O(6) is bonded in a linear geometry to one U(1) and one Te(1) atom. In the seventh O site, O(7) is bonded in a 4-coordinate geometry to one K(1), one U(1), and two equivalent Te(1) atoms.
K2U3(TeO7)2 crystallizes in the triclinic P-1 space group. K(1) is bonded to one O(3), one O(7), two equivalent O(1), and two equivalent O(2) atoms to form distorted KO6 octahedra that share corners with two equivalent U(2)O6 octahedra, corners with four equivalent U(1)O7 pentagonal bipyramids, and edges with two equivalent K(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 53-59°. The K(1)-O(3) bond length is 2.84 Å. The K(1)-O(7) bond length is 2.91 Å. There is one shorter (2.77 Å) and one longer (2.84 Å) K(1)-O(1) bond length. There is one shorter (2.83 Å) and one longer (2.87 Å) K(1)-O(2) bond length. There are two inequivalent U sites. In the first U site, U(1) is bonded to one O(2), one O(3), one O(5), one O(6), one O(7), and two equivalent O(4) atoms to form distorted UO7 pentagonal bipyramids that share  a cornercorner with one U(2)O6 octahedra, corners with four equivalent K(1)O6 octahedra,  an edgeedge with one U(2)O6 octahedra, and  an edgeedge with one U(1)O7 pentagonal bipyramid. The corner-sharing octahedral tilt angles range from 47-64°. The U(1)-O(2) bond length is 1.87 Å. The U(1)-O(3) bond length is 1.84 Å. The U(1)-O(5) bond length is 2.47 Å. The U(1)-O(6) bond length is 2.25 Å. The U(1)-O(7) bond length is 2.49 Å. There is one shorter (2.27 Å) and one longer (2.35 Å) U(1)-O(4) bond length. In the second U site, U(2) is bonded to two equivalent O(1), two equivalent O(4), and two equivalent O(5) atoms to form distorted UO6 octahedra that share corners with four equivalent K(1)O6 octahedra, corners with two equivalent U(1)O7 pentagonal bipyramids, and edges with two equivalent U(1)O7 pentagonal bipyramids. The corner-sharing octahedral tilt angles range from 53-59°. Both U(2)-O(1) bond lengths are 1.86 Å. Both U(2)-O(4) bond lengths are 2.22 Å. Both U(2)-O(5) bond lengths are 2.33 Å. Te(1) is bonded in a 3-coordinate geometry to one O(5), one O(6), and two equivalent O(7) atoms. The Te(1)-O(5) bond length is 1.92 Å. The Te(1)-O(6) bond length is 1.90 Å. There is one shorter (1.92 Å) and one longer (2.63 Å) Te(1)-O(7) bond length. There are seven inequivalent O sites. In the first O site, O(1) is bonded in a distorted single-bond geometry to two equivalent K(1) and one U(2) atom. In the second O site, O(2) is bonded in a distorted single-bond geometry to two equivalent K(1) and one U(1) atom. In the third O site, O(3) is bonded in a distorted bent 120 degrees geometry to one K(1) and one U(1) atom. In the fourth O site, O(4) is bonded in a distorted trigonal planar geometry to one U(2) and two equivalent U(1) atoms. In the fifth O site, O(5) is bonded in a trigonal planar geometry to one U(1), one U(2), and one Te(1) atom. In the sixth O site, O(6) is bonded in a linear geometry to one U(1) and one Te(1) atom. In the seventh O site, O(7) is bonded in a 4-coordinate geometry to one K(1), one U(1), and two equivalent Te(1) atoms.