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arXiv 1810.03368cond-mat.mtrl-sci
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基于电子结构的局部原子环境描述子

Electronic structure based descriptor for characterizing local atomic environments

Jan Jenke, Aparna P. A. Subramanyam, Marc Densow, Thomas Hammerschmidt, David G. Pettifor, Ralf Drautz

摘要:

局部原子环境的定量描述符通常需要用于原子数据的分析。局部原子环境的描述符理想地提供物理和化学直观的洞察力。这需要描述符,是原子几何形状和电子键形成之间的相互作用的低维表示。局域态密度(DOS)的矩将原子结构与电子结构和键化学联系起来。这使得有可能构建基于电子结构的局部原子环境的描述符,其与结合能具有直接关系。我们表明,低维的时刻描述符是足够的最低时刻,计算从最近的原子邻域,进行最大的贡献,当地的键能。在这里,我们构建的时刻描述符,项目的2-D地图上的局部原子环境的空间。我们详细讨论了各种原子环境的分离及其在地图中的连接。图中的距离可能与局部原子环境之间的能量差异有关,正如我们基于解析键级势(BOP)的分析考虑以及使用TB和密度泛函理论计算的数值评估所示。所提出的时刻描述符的可能应用包括分子动力学模拟中的局部原子环境的分类,用于开发和测试原子间势的结构集的选择,以及用于机器学习应用的描述符的构建。

英文摘要:

A quantitative descriptor of local atomic environments is often required for the analysis of atomistic data. Descriptors of the local atomic environment ideally provide physically and chemically intuitive insight. This requires descriptors that are low-dimensional representations of the interplay between atomic geometry and electronic bond formation. The moments of the local density of states (DOS) relate the atomic structure to the electronic structure and bond chemistry. This makes it possible to construct electronic structure based descriptors of the local atomic environment that have an immediate relation to the binding energy. We show that a low-dimensional moments-descriptor is sufficient as the lowest moments, calculated from the closest atomic neighborhood, carry the largest contributions to the local bond energy. Here, we construct moments-descriptors that project the space of local atomic environments on a 2-D map. We discuss in detail the separation of various atomic environments and their connections in the map. The distances in the map may be related to energy differences between local atomic environments as we show by analytic considerations based on analytic bond-order potentials (BOP) and by numerical assessment using TB and density-functional theory calculations. Possible applications of the proposed moments-descriptors include the classification of local atomic environments in molecular-dynamic simulations, the selection of structure sets for developing and testing interatomic potentials, as well as the construction of descriptors for machine-learning applications.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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