K2S2O5 crystallizes in the monoclinic P2_1/m space group. There are two inequivalent K sites. In the first K site, K(1) is bonded in a 7-coordinate geometry to one O(3), two equivalent O(2), and four equivalent O(1) atoms. In the second K site, K(2) is bonded in a 6-coordinate geometry to two equivalent O(1) and four equivalent O(2) atoms. There are two inequivalent S sites. In the first S site, S(1) is bonded in a trigonal non-coplanar geometry to one O(3) and two equivalent O(1) atoms. In the second S site, S(2) is bonded in a water-like geometry to two equivalent O(2) atoms. There are three inequivalent O sites. In the first O site, O(1) is bonded in a distorted single-bond geometry to one K(2), two equivalent K(1), and one S(1) atom. In the second O site, O(2) is bonded in a 4-coordinate geometry to one K(1), two equivalent K(2), and one S(2) atom. In the third O site, O(3) is bonded in a distorted single-bond geometry to one K(1) and one S(1) atom.
K2S2O5 crystallizes in the monoclinic P2_1/m space group. There are two inequivalent K sites. In the first K site, K(1) is bonded in a 7-coordinate geometry to one O(3), two equivalent O(2), and four equivalent O(1) atoms. The K(1)-O(3) bond length is 3.10 Å. Both K(1)-O(2) bond lengths are 3.09 Å. There are two shorter (2.81 Å) and two longer (3.31 Å) K(1)-O(1) bond lengths. In the second K site, K(2) is bonded in a 6-coordinate geometry to two equivalent O(1) and four equivalent O(2) atoms. Both K(2)-O(1) bond lengths are 2.89 Å. There are two shorter (2.74 Å) and two longer (2.98 Å) K(2)-O(2) bond lengths. There are two inequivalent S sites. In the first S site, S(1) is bonded in a trigonal non-coplanar geometry to one O(3) and two equivalent O(1) atoms. The S(1)-O(3) bond length is 1.48 Å. Both S(1)-O(1) bond lengths are 1.50 Å. In the second S site, S(2) is bonded in a water-like geometry to two equivalent O(2) atoms. Both S(2)-O(2) bond lengths are 1.51 Å. There are three inequivalent O sites. In the first O site, O(1) is bonded in a distorted single-bond geometry to one K(2), two equivalent K(1), and one S(1) atom. In the second O site, O(2) is bonded in a 4-coordinate geometry to one K(1), two equivalent K(2), and one S(2) atom. In the third O site, O(3) is bonded in a distorted single-bond geometry to one K(1) and one S(1) atom.