相关软件或概念:Olex2[1] (Version: Olex2-1.5); SHELXL[2] (Version: SHELXL-2019/3); PLATON[3] (Version: 241123) 最近,某高校友友的一个晶体数据,虽然已无AB级警报,但残余峰还比较大,如图1所示。
▲图1 数据概况 最大残余峰在苯并噻二唑的硫原子椭球形变方向,如图2所示。
▲图2 残余峰位置 观察三个残余峰位置,设计无序方案为苯并噻二唑基团绕C20-C17-C14-C13所在轴旋转的二重无序,用SAME指令和SIMU指令分别限制两个组分的几何结构和各向异性位移参数,最终结果如图3所示,残余峰从原来的1.1降为0.5,R因子也有所下降。
▲图3 无序处理最终结果 参考文献 [1]Dolomanov, O. V.; Bourhis, L. J.; Gildea, R. J.; Howard, J. A. K.; Puschmann,H. OLEX2: A complete structure solution,refinement and analysis program. J. Appl. Cryst. 2009, 42, 339–341. [2](a) Sheldrick, G. M. SHELXL-2019/3, Program for Crystal Structure Refinement,University of Göttingen, Germany, 2019. (b) Sheldrick, G. M. A short history ofSHELX. Acta Cryst. 2008, A64, 112–122. (c) Sheldrick, G. M.Crystal structure refinement with SHELXL.Acta Cryst. 2015, C71, 3–8. (d)Lübben, J.; Wandtke, C. M.; Hübschle, C. B.; Ruf, M.; Sheldrick, G. M.;Dittrich, B. Aspherical scattering factors for SHELXL – model, implementation and application. Acta Cryst. 2019, A75, 50–62. [3] (a) Spek, A. L. Single-crystal structure validationwith the program PLATON. J. Appl.Cryst. 2003, 36, 7–13. (b) Spek,A. L. Structure validation in chemical crystallography. Acta Cryst. 2009, D65, 148–155. (c) Spek, A. L. What makes a crystal structure reportvalid? Inorg. Chim. Acta 2018, 470, 232–237. (d) Spek, A. L. checkCIFvalidation ALERTS: what they mean and how to respond. Acta Cryst. 2020, E76, 1–11. 如需PDF文档,请从以下链接下载: 通过网盘分享的文件:无序示例-苯并噻二唑二重无序.pdf
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