3-Ethyl-1H-1,2,4-triazole-5(4H)-thione

The mol­ecule of the title compound, C(4)H(7)N(3)S, exists as the thione tautomer in the solid state. The asymmetric unit consits of one mol­ecule in which all atoms are located on a crystallographic mirror plane. In the crystal, adjacent mol­ecules are linked by N—H⋯N and N—H⋯S hydrogen bonds into chains running along the a axis. π–π stacking inter­actions between the triazole rings [centroid–centroid distance = 3.740 (1) Å and inter­planar distance = 3.376 Å] may further stabilize the structure.