K(USe3)2 crystallizes in the orthorhombic Immm space group. K(1) is bonded in a distorted body-centered cubic geometry to eight equivalent Se(2) atoms. U(1) is bonded in a 8-coordinate geometry to four equivalent Se(1) and four equivalent Se(2) atoms. There are two inequivalent Se sites. In the first Se site, Se(1) is bonded to four equivalent U(1) atoms to form a mixture of distorted corner and edge-sharing SeU4 trigonal pyramids. In the second Se site, Se(2) is bonded in a 6-coordinate geometry to two equivalent K(1), two equivalent U(1), and two equivalent Se(2) atoms.
K(USe3)2 crystallizes in the orthorhombic Immm space group. K(1) is bonded in a distorted body-centered cubic geometry to eight equivalent Se(2) atoms. All K(1)-Se(2) bond lengths are 3.40 Å. U(1) is bonded in a 8-coordinate geometry to four equivalent Se(1) and four equivalent Se(2) atoms. There are two shorter (2.89 Å) and two longer (2.98 Å) U(1)-Se(1) bond lengths. All U(1)-Se(2) bond lengths are 2.94 Å. There are two inequivalent Se sites. In the first Se site, Se(1) is bonded to four equivalent U(1) atoms to form a mixture of distorted corner and edge-sharing SeU4 trigonal pyramids. In the second Se site, Se(2) is bonded in a 6-coordinate geometry to two equivalent K(1), two equivalent U(1), and two equivalent Se(2) atoms. There is one shorter (2.71 Å) and one longer (2.82 Å) Se(2)-Se(2) bond length.