KPdCuSe5 crystallizes in the monoclinic P2_1/m space group. K(1) is bonded in a 9-coordinate geometry to one Se(3), four equivalent Se(2), and four equivalent Se(4) atoms. Pd(1) is bonded in a square co-planar geometry to two equivalent Se(1) and two equivalent Se(4) atoms. Cu(1) is bonded to one Se(1), one Se(3), and two equivalent Se(4) atoms to form CuSe4 tetrahedra that share  a cornercorner with one Se(2)K4Se trigonal bipyramid. There are four inequivalent Se sites. In the first Se site, Se(1) is bonded to two equivalent Pd(1), one Cu(1), and one Se(2) atom to form distorted corner-sharing SeCuPd2Se tetrahedra. In the second Se site, Se(2) is bonded to four equivalent K(1) and one Se(1) atom to form distorted SeK4Se trigonal bipyramids that share  a cornercorner with one Cu(1)Se4 tetrahedra, corners with four equivalent Se(2)K4Se trigonal bipyramids, and edges with four equivalent Se(2)K4Se trigonal bipyramids. In the third Se site, Se(3) is bonded in a 4-coordinate geometry to one K(1), one Cu(1), and two equivalent Se(4) atoms. In the fourth Se site, Se(4) is bonded in a 5-coordinate geometry to two equivalent K(1), one Pd(1), one Cu(1), and one Se(3) atom.
KPdCuSe5 crystallizes in the monoclinic P2_1/m space group. K(1) is bonded in a 9-coordinate geometry to one Se(3), four equivalent Se(2), and four equivalent Se(4) atoms. The K(1)-Se(3) bond length is 3.62 Å. There are a spread of K(1)-Se(2) bond distances ranging from 3.39-3.74 Å. There are two shorter (3.50 Å) and two longer (3.66 Å) K(1)-Se(4) bond lengths. Pd(1) is bonded in a square co-planar geometry to two equivalent Se(1) and two equivalent Se(4) atoms. Both Pd(1)-Se(1) bond lengths are 2.50 Å. Both Pd(1)-Se(4) bond lengths are 2.50 Å. Cu(1) is bonded to one Se(1), one Se(3), and two equivalent Se(4) atoms to form CuSe4 tetrahedra that share  a cornercorner with one Se(2)K4Se trigonal bipyramid. The Cu(1)-Se(1) bond length is 2.50 Å. The Cu(1)-Se(3) bond length is 2.40 Å. Both Cu(1)-Se(4) bond lengths are 2.39 Å. There are four inequivalent Se sites. In the first Se site, Se(1) is bonded to two equivalent Pd(1), one Cu(1), and one Se(2) atom to form distorted corner-sharing SeCuPd2Se tetrahedra. The Se(1)-Se(2) bond length is 2.39 Å. In the second Se site, Se(2) is bonded to four equivalent K(1) and one Se(1) atom to form distorted SeK4Se trigonal bipyramids that share  a cornercorner with one Cu(1)Se4 tetrahedra, corners with four equivalent Se(2)K4Se trigonal bipyramids, and edges with four equivalent Se(2)K4Se trigonal bipyramids. In the third Se site, Se(3) is bonded in a 4-coordinate geometry to one K(1), one Cu(1), and two equivalent Se(4) atoms. Both Se(3)-Se(4) bond lengths are 2.46 Å. In the fourth Se site, Se(4) is bonded in a 5-coordinate geometry to two equivalent K(1), one Pd(1), one Cu(1), and one Se(3) atom.