K2H2Se(O5I)2 crystallizes in the monoclinic C2/c space group. K(1) is bonded in a 9-coordinate geometry to one O(3), one O(4), two equivalent O(1), two equivalent O(5), and three equivalent O(2) atoms. H(1) is bonded in a single-bond geometry to one O(1) and one O(3) atom. Se(1) is bonded in a tetrahedral geometry to two equivalent O(4) and two equivalent O(5) atoms. There are five inequivalent O sites. In the first O site, O(2) is bonded in a 4-coordinate geometry to three equivalent K(1) and one I(1) atom. In the second O site, O(3) is bonded in a distorted trigonal non-coplanar geometry to one K(1), one H(1), and one I(1) atom. In the third O site, O(4) is bonded in a distorted trigonal non-coplanar geometry to one K(1), one Se(1), and one I(1) atom. In the fourth O site, O(5) is bonded in a distorted single-bond geometry to two equivalent K(1) and one Se(1) atom. In the fifth O site, O(1) is bonded in a distorted single-bond geometry to two equivalent K(1), one H(1), and one I(1) atom. I(1) is bonded in a 4-coordinate geometry to one O(1), one O(2), one O(3), and one O(4) atom.
K2H2Se(O5I)2 crystallizes in the monoclinic C2/c space group. K(1) is bonded in a 9-coordinate geometry to one O(3), one O(4), two equivalent O(1), two equivalent O(5), and three equivalent O(2) atoms. The K(1)-O(3) bond length is 2.96 Å. The K(1)-O(4) bond length is 2.81 Å. There is one shorter (2.89 Å) and one longer (3.21 Å) K(1)-O(1) bond length. There is one shorter (2.89 Å) and one longer (3.37 Å) K(1)-O(5) bond length. There are a spread of K(1)-O(2) bond distances ranging from 2.80-3.22 Å. H(1) is bonded in a single-bond geometry to one O(1) and one O(3) atom. The H(1)-O(1) bond length is 1.01 Å. The H(1)-O(3) bond length is 1.73 Å. Se(1) is bonded in a tetrahedral geometry to two equivalent O(4) and two equivalent O(5) atoms. Both Se(1)-O(4) bond lengths are 1.69 Å. Both Se(1)-O(5) bond lengths are 1.67 Å. There are five inequivalent O sites. In the first O site, O(2) is bonded in a 4-coordinate geometry to three equivalent K(1) and one I(1) atom. The O(2)-I(1) bond length is 1.80 Å. In the second O site, O(3) is bonded in a distorted trigonal non-coplanar geometry to one K(1), one H(1), and one I(1) atom. The O(3)-I(1) bond length is 1.83 Å. In the third O site, O(4) is bonded in a distorted trigonal non-coplanar geometry to one K(1), one Se(1), and one I(1) atom. The O(4)-I(1) bond length is 2.46 Å. In the fourth O site, O(5) is bonded in a distorted single-bond geometry to two equivalent K(1) and one Se(1) atom. In the fifth O site, O(1) is bonded in a distorted single-bond geometry to two equivalent K(1), one H(1), and one I(1) atom. The O(1)-I(1) bond length is 1.97 Å. I(1) is bonded in a 4-coordinate geometry to one O(1), one O(2), one O(3), and one O(4) atom.