Preparation and Structure Characterization of 4-Amino-1,2,4-triazol-5-one Hydrate

4-Amino-1,2,4-triazol-5-one hydrate (ATO·H2O) was prepared and its structure was analyzed by four-circle diffraction measurement. The obtained results show that the crystal belongs to the triclinic crystal system, space group P 1 with crystal parameters a = 6.432(1), b = 6.551(1), c = 6.740(1) A; α= 68.04(1), β = 82.18(1), γ = 81.90(1)°, V = 259.7(7) A3; Z = 2; Dc = 1.510 g/cm3; μ = 0.131 mm-1; F(000) = 124. ATO·H2O was characterized by FT-IR analysis, X-ray diffraction analysis, and single crystal diffraction analysis.