5-[4-(1H-Imidazol-1-yl)phen-yl]-2H-tetra-zole dihydrate.

In the title compound, C(10)H(8)N(6)·2H(2)O, the central aromatic ring makes dihedral angles of 23.59 (15) and 16.99 (16)° with the terminal imidazole and tetra-zole rings, respectively, which are themselves almost coplanar [dihedral angle = 6.61 (18)°]. Two H atoms of the two water mol-ecules are half occupied. In the crystal packing, weak inter-molecular O-H⋯N, O-H⋯O and N-H⋯N hydrogen bonds and π-π stacking inter-actions [centroid-centroid distances of 3.73 (4) Å between benzene rings and 3.66 (3) Å between imidazole and tetra-zole rings] are observed.