标题： 截断函数对Tersoff势在热传导分子动力学模拟中的影响 显示英文标题

标题： Effects of Cutoff Functions of Tersoff Potentials on Molecular Dynamics Simulations of Thermal Transport

摘要： 过去关于热传导的分子动力学研究主要使用了Stillinger-Weber势函数。 随着材料不断缩小，其性质越来越依赖于缺陷和表面效应。 不幸的是， Stillinger-Weber势函数最适合用于类似金刚石立方体的体晶体。 它们无法表示许多亚稳相的能量，也无法准确预测缺陷和表面区域的热力学性质。 为了研究这些区域可能主导热传导的纳米结构材料，Tersoff势函数在表示这些结构方面的准确性更为理想。 基于对GaN系统中热传导的分析，我们证明了现有Tersoff势函数的截断函数可能导致确定热导率的问题。 为了解决这个问题，提出了改进的截断方案并进行了评估。 显示英文摘要

摘要： Past molecular dynamics studies of thermal transport have predominantly used Stillinger-Weber potentials. As materials continuously shrink, their properties increasingly depend on defect and surface effects. Unfortunately, Stillinger-Weber potentials are best used for diamond-cubic-like bulk crystals. They cannot represent the energies of many metastable phases, nor can they accurately predict the energetics of defective and surface regions. To study nanostructured materials, where these regions can dominate thermal transport, the accuracy of Tersoff potentials in representing these structures is more desirable. Based upon an analysis of thermal transport in a GaN system, we demonstrate that the cutoff function of the existing Tersoff potentials may lead to problems in determining the thermal conductivity. To remedy this issue, improved cutoff schemes are proposed and evaluated.