Pyrimethanil was prepared and the single crystal was obtained from the ethanol as solvent. The crystal structure of the pyrimethanil was detected by single crystal X-ray diffraction. The crystal belongs to triclinic symmetry with space group P2(1)/n and crystal parameters of a＝0.7532(1) nm, b＝1.1701(1) nm, c＝1.4640(2) nm, α＝68.361(2)°, β＝85.554(2)°, γ＝71.291(2)°, V＝1.1348(2) nm³, D_c＝1.166 g•cm^－3, Z＝4, F(000)＝424, μ＝0.072 mm^－1. A crystal unit of the title compound was selected as the initial structure, and it was fully optimized. The atomic charges, total energy and frontier orbital energy were also discussed.

Key words: pyrimethanil, synthesis, crystal structure, quantum chemical calculation