KCu2H2(SO5)2 crystallizes in the monoclinic C2/m space group. K(1) is bonded to two equivalent O(1), two equivalent O(4), and four equivalent O(2) atoms to form distorted KO8 hexagonal bipyramids that share corners with four equivalent S(1)O4 tetrahedra, edges with four equivalent Cu(1)O6 octahedra, and edges with two equivalent S(1)O4 tetrahedra. Cu(1) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(3) atoms to form distorted CuO6 octahedra that share corners with four equivalent S(1)O4 tetrahedra, edges with two equivalent K(1)O8 hexagonal bipyramids, and edges with two equivalent Cu(1)O6 octahedra. H(1) is bonded in a single-bond geometry to one O(3) atom. S(1) is bonded to one O(1), one O(4), and two equivalent O(2) atoms to form SO4 tetrahedra that share corners with two equivalent K(1)O8 hexagonal bipyramids, corners with four equivalent Cu(1)O6 octahedra, and  an edgeedge with one K(1)O8 hexagonal bipyramid. The corner-sharing octahedral tilt angles range from 42-50°. There are four inequivalent O sites. In the first O site, O(1) is bonded in a distorted single-bond geometry to one K(1), two equivalent Cu(1), and one S(1) atom. In the second O site, O(2) is bonded in a 3-coordinate geometry to one K(1), one Cu(1), and one S(1) atom. In the third O site, O(3) is bonded in a distorted trigonal non-coplanar geometry to two equivalent Cu(1) and one H(1) atom. In the fourth O site, O(4) is bonded in a single-bond geometry to one K(1) and one S(1) atom.
KCu2H2(SO5)2 crystallizes in the monoclinic C2/m space group. K(1) is bonded to two equivalent O(1), two equivalent O(4), and four equivalent O(2) atoms to form distorted KO8 hexagonal bipyramids that share corners with four equivalent S(1)O4 tetrahedra, edges with four equivalent Cu(1)O6 octahedra, and edges with two equivalent S(1)O4 tetrahedra. Both K(1)-O(1) bond lengths are 2.82 Å. Both K(1)-O(4) bond lengths are 2.96 Å. All K(1)-O(2) bond lengths are 2.82 Å. Cu(1) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(3) atoms to form distorted CuO6 octahedra that share corners with four equivalent S(1)O4 tetrahedra, edges with two equivalent K(1)O8 hexagonal bipyramids, and edges with two equivalent Cu(1)O6 octahedra. Both Cu(1)-O(1) bond lengths are 2.50 Å. Both Cu(1)-O(2) bond lengths are 1.97 Å. Both Cu(1)-O(3) bond lengths are 1.89 Å. H(1) is bonded in a single-bond geometry to one O(3) atom. The H(1)-O(3) bond length is 0.99 Å. S(1) is bonded to one O(1), one O(4), and two equivalent O(2) atoms to form SO4 tetrahedra that share corners with two equivalent K(1)O8 hexagonal bipyramids, corners with four equivalent Cu(1)O6 octahedra, and  an edgeedge with one K(1)O8 hexagonal bipyramid. The corner-sharing octahedral tilt angles range from 42-50°. The S(1)-O(1) bond length is 1.48 Å. The S(1)-O(4) bond length is 1.46 Å. Both S(1)-O(2) bond lengths are 1.52 Å. There are four inequivalent O sites. In the first O site, O(1) is bonded in a distorted single-bond geometry to one K(1), two equivalent Cu(1), and one S(1) atom. In the second O site, O(2) is bonded in a 3-coordinate geometry to one K(1), one Cu(1), and one S(1) atom. In the third O site, O(3) is bonded in a distorted trigonal non-coplanar geometry to two equivalent Cu(1) and one H(1) atom. In the fourth O site, O(4) is bonded in a single-bond geometry to one K(1) and one S(1) atom.