Development of bond-order potentials that can reproduce the elastic constants and melting point of silicon for classical molecular dynamics simulation
Development of bond-order potentials that can reproduce the elastic constants and melting point of silicon for classical molecular dynamics simulation
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DOI：
10.1016/j.commatsci.2006.07.013
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发表时间：
2007-04-01
影响因子：
3.3
通讯作者：
Sakai, S.
中科院分区：
文献类型：
--
作者：
Kumagai, T.;Izumi, S.;Sakai, S.
特尔索夫势是硅原子间最广泛使用的势之一。然而，它对金刚石硅的弹性常数和熔点的描述很差，这是众所周知的。在本研究中，发展了三种键级型原子间相互作用势：第一种是用Tersoff势函数形式来拟合弹性常数，第二种是用Tersoff势函数形式来拟合弹性常数和熔点，第三种是用改进后的Tersoff势函数形式来拟合弹性常数和熔点。所有的发展势都很好地再现了金刚石硅的弹性常数以及硅多型的结合能和平衡键长。第三个势可以重现熔点，而第二个势不能重现熔点。用第三势计算出的弹性常数和熔点分别为C-11=166.4 Gpa，C-12=65.3 Gpa，C-44=77.1 Gpa，T-m=1681K。同时发现，用原Tersoff势函数只能再现弹性常数，而我们提出的与角度有关的项是再现熔点的关键。(C)2006爱思唯尔B.V.保留所有权利。
The Tersoff potential is one of the most widely used interatomic potentials for silicon. However, its poor description of the elastic constants and melting point of diamond silicon is well known. In this research, three bond-order type interatomic potentials have been developed: the first one is fitted to the elastic constants by employing the Tersoff potential function form, the second one is fitted to both the elastic constants and melting point by employing the Tersoff potential function form and the third one is fitted to both the elastic constants and melting point by employing the modified Tersoff potential function form in which the angular-dependent term is improved. All of developed potentials well reproduce the elastic constants of diamond silicon as well as the cohesive energies and equilibrium bond lengths of silicon polytypes. The third potential can reproduce the melting point, while the second one cannot reproduce that. The elastic constants and melting point calculated using the third potential turned out to be C-11 = 166.4 GPa, C-12 = 65.3 GPa, C-44 = 77.1 GPa and T-m = 1681 K. It was also found that only elastic constants can be reproduced using the original Tersoff potential function, and that our proposed angular-dependent term is a key to reproducing the melting point. (c) 2006 Elsevier B.V. All rights reserved.