دورية أكاديمية
A mixed phosphine sulfide/selenide structure as an instructional example for how to evaluate the quality of a model
| العنوان: | A mixed phosphine sulfide/selenide structure as an instructional example for how to evaluate the quality of a model |
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| المؤلفون: | Sean Parkin, Jeremy Cunningham, Brian Rawls, John E. Bender, Richard J. Staples, Shannon M. Biros |
| المصدر: | Acta Crystallographica Section E: Crystallographic Communications, Vol 79, Iss 4, Pp 246-253 (2023) |
| بيانات النشر: | International Union of Crystallography, 2023. |
| سنة النشر: | 2023 |
| المجموعة: | LCC:Crystallography |
| مصطلحات موضوعية: | checkcif alerts, f2obs vs f2calc, omit command, outliers, displacement ellipsoids, solid solution, disordered electron density, standard interatomic distances, crystal structure, Crystallography, QD901-999 |
| الوصف: | This paper compares variations on a structure model derived from an X-ray diffraction data set from a solid solution of chalcogenide derivatives of cis-1,2-bis(diphenylphosphanyl)ethylene, namely, 1,2-(ethene-1,2-diyl)bis(diphenylphoshpine sulfide/selenide), C26H22P2S1.13Se0.87. A sequence of processes are presented to ascertain the composition of the crystal, along with strategies for which aspects of the model to inspect to ensure a chemically and crystallographically realistic structure. Criteria include mis-matches between Fobs2 and Fcalc2, plots of |Fobs| vs |Fcalc|, residual electron density, checkCIF alerts, pitfalls of the OMIT command used to suppress ill-fitting data, comparative size of displacement ellipsoids, and critical inspection of interatomic distances. Since the structure is quite small, solves easily, and presents a number of readily expressible refinement concepts, we feel that it would make a straightforward and concise instructional piece for students learning how to determine if their model provides the best fit for the data and show students how to critically assess their structures. |
| نوع الوثيقة: | article |
| وصف الملف: | electronic resource |
| اللغة: | English |
| تدمد: | 2056-9890 20569890 |
| Relation: | http://scripts.iucr.org/cgi-bin/paper?S2056989023002700; https://doaj.org/toc/2056-9890 |
| DOI: | 10.1107/S2056989023002700 |
| URL الوصول: | https://doaj.org/article/8d8b2dd08f1e4a10a2efaccac4061147 |
| رقم الأكسشن: | edsdoj.8d8b2dd08f1e4a10a2efaccac4061147 |
| قاعدة البيانات: | Directory of Open Access Journals |
Full Text Finder | تدمد: | 20569890 |
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| DOI: | 10.1107/S2056989023002700 |