ObJective: As the research obJect of chlorogenic acid

using X-ray powder diffraction analysis of its crystal structure. Method: In use of XPRD at step of 0.01° scan and get a high-resolution diffraction pattern. Result: Through indexing to identify the crystal system and the space group

then used monte carlo simulated annealing method and rietveld refinement to determine the three-dimensional crystal structure and fractional coordinates of each atom in crystal cell. Conclusion: Powder crystal structure of chlorogenic acid is orthorhombic

space group Pna21 with unit cell dimensions a=36.132

b=11.709

c=8.152

ɑ=90°

β=90°

r=90°

V=3 448.86 3

Z=4.