National Energy Technology Laboratory, Pittsburgh, Pennsylvania 15236, USA.
J Phys Chem A. 2010 May 13;114(18):5855-61. doi: 10.1021/jp911867r.
ReaxFF provides a method to describe bond-breaking and bond-forming events that can be applied to large-scale molecular dynamics simulations. This article describes the development of a ReaxFF potential for cobalt. This potential is transferable to a wide variety of cobalt systems, including various crystal structures, surfaces, clusters, and defects. The potential parameters were obtained from an extensive set of ab initio calculations. We have tested these parameters against additional DFT calculations not included in the fitting data set and found that ReaxFF provides similar or superior agreement with the DFT results compared to accepted embedded atom method descriptions for Co. We validated this potential by performing large-scale molecular dynamics simulations to predict the melting point, diffusion coefficients for the liquid as a function of temperature, and vacancy-mediated diffusion coefficients in the solid as a function of temperature and vacancy concentration. Results are compared with other theoretical methods and experiments where available. Since the ReaxFF method allows straightforward extensions to alloys and heterogeneous materials, including first-row elements, the ReaxFF parameters described here provide a foundation for the simulation of a wide range of Co-containing materials.
ReaxFF 提供了一种描述键断裂和形成事件的方法，可应用于大规模分子动力学模拟。本文描述了一种钴的 ReaxFF 势的开发。该势可转移到多种钴体系，包括各种晶体结构、表面、团簇和缺陷。势参数是通过大量从头算计算获得的。我们已经针对未包含在拟合数据集的其他 DFT 计算测试了这些参数，并发现与 Co 的公认嵌入原子方法描述相比，ReaxFF 与 DFT 结果具有相似或更好的一致性。我们通过进行大规模分子动力学模拟来验证该势，以预测熔点、液体的扩散系数随温度的变化以及空位中介扩散系数随温度和空位浓度的变化。结果与其他理论方法和实验结果进行了比较。由于 ReaxFF 方法可以直接扩展到合金和包括第一行元素在内的非均匀材料，因此这里描述的 ReaxFF 参数为模拟各种含 Co 材料提供了基础。
