中文摘要：

4-氨基-1，2，4-三唑-5-酮（ATO）与硫氰酸钾、氯甲酸乙酯在乙酸乙酯中反应，合成了4-（1，2，4-三唑-5-酮-4-基）-3-硫代脲酸乙酯，在室温下采用缓慢蒸发溶剂二甲基甲酰胺得到合适的可用于X射线衍射的单晶．晶体属六方系，空间群为R-3，晶体结构参数为α=2．60524（7）nm，b=2．60524（7）nm，c=0．82579（6）nm，γ=120°，V=4．8540（4）nm^3，Dc=1．442g／cm^3，g=0．300mm^-1，F（000）=2190，Z=18，R1=0．0569，wR2=0．1424．选取标题化合物的一个结构单元作为初始模型，运用Gaussian 03程序对化合物进行了HF／6-311G，MP2／6-311G和B3LYP／6-311G水平的几何全优化，并对其原子电荷及自然键轨道（NBO）进行了分析．

英文摘要：

4-（1,2,4-Triazole-5-one-4-yl）-3-thiourea carboxylic acid ethyl ester was synthesized by mixing 4-amino-1,2,4-triazole-5-one （ATO）, potassium thiocyanate and ethyl chloroformate in ethyl acetate. Single crystals suitable for X-ray measurement were obtained by slow evaporation of the solvent dimethylformamide at room temperature. The crystal belongs to rhombohedral symmetry with space group R-3 and crystal parameters of α=2.60524（7） nm, b=2.60524（7） nm, c=0.82579（6） nm, y= 120°, V=4.8540（4） nm^3, Dc= 1.442 g/cm^3,/μ=0.300 mm^-1, F（000）=2190, Z=18, R1=0.0569, wR2=0.1424. A crystal unit of the title compound was selected as the initial structure, and it was fully optimized by HF/6-311G, MP2/6-311G and B3LYP/6-311G methods in Gaussian 03 package, and the atomic charges and natural bond orbital （NBO） analysis were also discussed.