总结了粉末衍射从头晶体结构测定中的问题与对策,并采用常规X射线粉末衍射数据,从头测定了配合物[Co(NH_3)_5Br]Br_2的晶体结构.在指标化与分峰基础上,采用直接法获得含7个独立非H原子的粗结构.在10°～80°(2θ)范围内用3500个强度数据对38个参数作Rietveld精修,得到了[Co(NH_3)_5Br]Br_2的晶体结构.其晶胞参数为:a=1.3692(1)nm,b=1.0707(1)nm,c=0.6940(1)nm,V=1.0175(1)nm~3,Z=4.空间群:Pnma,品质因子:M_20=49,F_30=93(0.0075,43),结构吻合因子:R_p=0.066,R_(wp)=0.090,R_F=0.041,R_B=0.042. The crystal structure of complex [Co (NH_3) _5Br] Br_2 was determined ab initio from the conventional X-ray powder diffraction data.According to the indexization and peak-point analysis, Direct method was used to obtain a crude structure containing seven independent non-H atoms. Rietveld refinement of 38 parameters with 3500 intensity data in the range of 10 ° -80 ° (2θ) gave [Co (NH_3) _5Br] Br_2 The lattice parameters of the crystal structure are as follows: a = 1.3692 (1) nm, b = 1.0707 nm, c = 0.6940 nm, V = 1.0175 nm, Pnma, quality factor: M_20 = 49, F_30 = 93 (0.0075,43). The structural anastomosis factors: R_p = 0.066, R_ (wp) = 0.090, R_F = 0.041, R_B = 0.042.