Two dimorphs of 5-methyl­sulfanyl-1H-tetrazole

5-Methyl­sulfanyl-1H-tetrazole, C2H4N4S, crystallizes in dimor­phic forms; the α-form crystallizes at room temperature in the monoclinic crystal system, space group P21/m, and the β-form crystallizes by sublimation at 423 K in the orthorhombic crystal system, space group Pbcm. In both forms, the mol­ecules occupy crystallographic mirror planes and are connected to one another via N—H⋯N hydrogen bonds, the amino H atoms being disordered. The two forms differ from one another in their packing; there are polar layers in the α-form and non-polar layers in the β-form.