相关软件或概念:Olex2[1] (Version: Olex2-1.5); SHELXL[2] (Version: SHELXL-2019/3); PLATON[3] (Version: 60124) 案例来源:CCDC2340347, DOI: 10.5517/ccdc.csd.cc2jkb2j. 该结构中有一个环己基,其中有两个碳做了二组分无序处理,如图1所示。
▲图1 环己基中两个碳原子二组分无序
▲图2 B级警报PLAT338 该警报是指环己基的平均扭转角太小了,观察该环己基,可以看出与已做无序处理的两个原子直接相连的两个碳原子的原子椭球也有较大变形,考虑对四个碳原子做无序处理,看看能否解决该问题,发现是可以消除上述B级警报的,甚至C级警报PLAT230(参阅推文“CheckCIF-PLAT230”)也消除了,如图3所示。
▲图3 环己基中四个碳原子二组分无序结果 相关视频: 单晶结构解析练习117(数据还原):https://www.bilibili.com/video/BV1xx421C7P9 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 **ysis 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.
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