The asymmetric unit of the title compound, C(4)H(5)N(7), comprises two independent but virtually superimposable mol-ecules. Each mol-ecule is planar with the dihedral angles between the five-membered rings being 2.8 (3) and 2.1 (3)°. The crystal structure is formed by an extensive network of relatively strong N-H⋯N hydrogen-bond inter-actions. Individual mol-ecules are arranged into supra-molecular zigzag chains running parallel to [001] by way of the strongest N-H⋯N inter-actions. Adjacent chains are inter-connected by rather long (D⋯A distances range from ca 3.00 to 3.03 Å) but highly directional (inter-action angles above ca 173°) hydrogen bonds forming a supra-molecular layer in the bc plane.