KUSi2O7 crystallizes in the tetragonal P4/mbm space group. K(1) is bonded in a 10-coordinate geometry to two equivalent O(4) and eight equivalent O(2) atoms. U(1) is bonded to one O(3), one O(5), and four equivalent O(2) atoms to form UO6 octahedra that share corners with two equivalent U(1)O6 octahedra and corners with four equivalent Si(1)O4 tetrahedra. The corner-sharing octahedra are not tilted. Si(1) is bonded to one O(1), one O(4), and two equivalent O(2) atoms to form SiO4 tetrahedra that share corners with two equivalent U(1)O6 octahedra and corners with two equivalent Si(1)O4 tetrahedra. The corner-sharing octahedral tilt angles are 26°. There are five inequivalent O sites. In the first O site, O(5) is bonded in a linear geometry to two equivalent U(1) atoms. In the second O site, O(1) is bonded in a linear geometry to two equivalent Si(1) atoms. In the third O site, O(2) is bonded in a distorted bent 150 degrees geometry to two equivalent K(1), one U(1), and one Si(1) atom. In the fourth O site, O(3) is bonded in a linear geometry to two equivalent U(1) atoms. In the fifth O site, O(4) is bonded in a distorted bent 150 degrees geometry to two equivalent K(1) and two equivalent Si(1) atoms.
KUSi2O7 crystallizes in the tetragonal P4/mbm space group. K(1) is bonded in a 10-coordinate geometry to two equivalent O(4) and eight equivalent O(2) atoms. Both K(1)-O(4) bond lengths are 3.09 Å. There are four shorter (3.04 Å) and four longer (3.17 Å) K(1)-O(2) bond lengths. U(1) is bonded to one O(3), one O(5), and four equivalent O(2) atoms to form UO6 octahedra that share corners with two equivalent U(1)O6 octahedra and corners with four equivalent Si(1)O4 tetrahedra. The corner-sharing octahedra are not tilted. The U(1)-O(3) bond length is 2.09 Å. The U(1)-O(5) bond length is 2.09 Å. All U(1)-O(2) bond lengths are 2.19 Å. Si(1) is bonded to one O(1), one O(4), and two equivalent O(2) atoms to form SiO4 tetrahedra that share corners with two equivalent U(1)O6 octahedra and corners with two equivalent Si(1)O4 tetrahedra. The corner-sharing octahedral tilt angles are 26°. The Si(1)-O(1) bond length is 1.63 Å. The Si(1)-O(4) bond length is 1.66 Å. Both Si(1)-O(2) bond lengths are 1.63 Å. There are five inequivalent O sites. In the first O site, O(5) is bonded in a linear geometry to two equivalent U(1) atoms. In the second O site, O(1) is bonded in a linear geometry to two equivalent Si(1) atoms. In the third O site, O(2) is bonded in a distorted bent 150 degrees geometry to two equivalent K(1), one U(1), and one Si(1) atom. In the fourth O site, O(3) is bonded in a linear geometry to two equivalent U(1) atoms. In the fifth O site, O(4) is bonded in a distorted bent 150 degrees geometry to two equivalent K(1) and two equivalent Si(1) atoms.