arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 1604.01577cond-mat.mtrl-sci
收藏

基于p阶矩近似的嵌入原子方法

A New Embedded-Atom Method Approach Based On the p-th Moment Approximation

Kun Wang, Wenjun Zhu, Shifang Xiao, Jun Chen, Wangyu Hu

摘要:

具有合适原子间相互作用势的大尺度原子模拟被各个领域的科学家和工程师广泛采用。快速生成高质量的原子间相互作用势是当前迫切需要解决的问题,这在很大程度上依赖于势构造方法和算法的发展。为了使原子间相互作用势具有更好的可传递性,人们提出了原子间相互作用势模型,并采用解析法、力匹配法、多目标优化法等方法对模型进行了参数化。在不明显降低描述目标系统的精度的情况下,更少的拟合参数(FP)的潜力在物理上更合理。因此,研究减少FP数的方法有助于理解模拟系统的基本物理,并将模拟系统的构造方法推广到其他类似系统。然而,很少有报道的作品集中在减少FP的数量,而不影响精度的方法。本文从两个方面讨论了在保证精度的前提下减少FP数的方法。首先,改进了嵌入原子法(EAM)势模型的物理构造思想,使势模型在不引入过多FP的情况下具有更强的鲁棒性、灵活性和可扩展性;其次,采用了相对于目标参考数据库更小的参考数据集(SRD)来描述铝合金的力学行为。

英文摘要:

Large scale atomistic simulations with suitable interatomic potentials are widely employed by scientists or engineers of different areas. Quick generation of high-quality interatomic potentials is of urgent need under present circumstances, which largely relies on the developments of potential construction methods and algorithms in this area. Quantities of interatomic potential models have been proposed and parameterized with various methods, such as analytic method, force-matching approach and multi-object optimization method, in order to make the potentials more transferable. Without apparently lowing precisions for describing the target system, potentials of fewer fitting parameters (FPs) are somewhat more physically reasonable. Thus, studying methods of reducing FP number is helpful to understand the underline physics of simulated systems and generalize the construction methods to other similar systems. However, few reported works concentrate on methods of reducing the number of FPs without affecting precisions. In this work, the methods of reducing the FP number while keeping the precisions are discussed from two aspects. Firstly, the physical ideas of constructions of the embedded-atom method (EAM) potential model are modified to make the potential more robust, flexible and scalable without introducing too many FPs.Secondly, the smaller reference data set (SRD), compared with the target reference database for describing the mechanical behaviors of aluminum, is employed in our construction procedures.

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。

↑