基于粉末X射线衍射的7-ADCA晶体结构解析改进

改进探测器短时间内获得7-ADCA粉末衍射谱图,自动寻峰并运用Dicvol91进行指标化,构建两性离子态分子模型,增加参数精修晶胞,实现7-ADCA多晶衍射结构解析的改进.结果表明:与前期工作相比,晶体的晶系、空间群和晶胞参数基本不变,但原子空间坐标变化显著,Rwp值由14.95%降到7.78%,得到更为准确的晶体结构模型.该模型可以合理解释7-ADCA晶体生长特性.

Improvement of 7-ADCA Crystal Structure Determination Based on X-ray Powder Diffraction

The improvement of polycrystal diffraction structure of 7-ADCA was realized tby obtaining the X ray powder diffraction pattern within shorter time after carrying out improvement in probe, searching peaks automatically and indexing the pattern by Dicvol91, establishing the molecular model as a zwitterionic form, and refining the cell with more parameters. The results showed that compared to the previous work, the system, space group and unit cell parameters are nearly invariable, while the Rwp decreases from 14.95% to 7.78% because the fraction coordinate of each atom in the unit cell changes significantly. Finally, a better crystal structural model of 7-ADCA was obtained which can explain its growth characteristics reasonably.