2,2′-Bi-1,3,4-thiadiazole-5,5′-diamine tetrahydrate

In the title compound, C4H4N6S2·4H2O, the complete organic molecule is generated by crystallographic twofold symmetry and the dihedral angle between the aromatic rings is 10.24 (3)°. In the crystal, intermolecular N—H...N, N—H...O, O—H...N and O—H...O hydrogen bonds and aromatic π–π stacking interactions [centroid–centroid separations = 3.530 (3) and 3.600 (3) ] are observed.