Suresh Ashwin, Yörük Emre, Cabaj Małgorzata K, Brázda Petr, Výborný Karel, Sedláček Ondřej, Müller Christian, Chintakindi Hrushikesh, Eigner Václav, Palatinus Lukáš
Institute of Physics of the Czech Academy of Sciences, Prague, Czech Republic.
Faculty of Mathematics and Physics, Charles University, Prague, Czech Republic.
Nat Commun. 2024 Oct 21;15(1):9066. doi: 10.1038/s41467-024-53448-2.
Conventional refinement strategies used for three-dimensional electron diffraction (3D ED) data disregard the bonding effects between the atoms in a molecule by assuming a pure spherical model called the Independent Atom model (IAM) and may lead to an inaccurate or biased structure. Here we show that it is possible to perform a refinement going beyond the IAM with electron diffraction data. We perform kappa refinement which models charge transfers between atoms while assuming a spherical model. We demonstrate the procedure by analysing five inorganic samples; quartz, natrolite, borane, lutecium aluminium garnet, and caesium lead bromide. Implementation of kappa refinement improved the structure model obtained over conventional IAM refinements and provided information on the ionisation of atoms. The results were validated against periodic DFT calculations. The work presents an extension of the conventional refinement of 3D ED data for a more accurate structure model which enables charge density information to be extracted.
用于三维电子衍射（3D ED）数据的传统精修策略通过假设一个称为独立原子模型（IAM）的纯球形模型，忽略了分子中原子之间的键合效应，这可能导致结构不准确或有偏差。在此我们表明，利用电子衍射数据可以进行超越IAM的精修。我们进行κ精修，它在假设球形模型的同时对原子间的电荷转移进行建模。我们通过分析五个无机样品（石英、钠沸石、硼烷、镥铝石榴石和溴化铯铅）来演示该过程。κ精修的实施改进了相对于传统IAM精修所获得的结构模型，并提供了有关原子电离的信息。结果通过周期性密度泛函理论（DFT）计算进行了验证。这项工作展示了对3D ED数据传统精修的扩展，以获得更准确的结构模型，从而能够提取电荷密度信息。
