Composition-dependent interatomic potentials: A systematic approach to modelling multicomponent alloys
Composition-dependent interatomic potentials: A systematic approach to modelling multicomponent alloys
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成分相关的原子间势：多组分合金建模的系统方法
DOI：
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发表时间：
2009
期刊：
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通讯作者：
Alfredo Caro
中科院分区：
文献类型：
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作者：
B. Sadigh;Paul Erhart;A. Stukowski;Alfredo Caro
我们提出了一个简单的方案来构建多组分系统的成分依赖的原子间势，当叠加到纯元素的电位上时，不仅可以再现在整个浓度范围内的固溶体的混合热，而且可以再现包括金属间相在内的更广泛的配置的能量。我们表明，在集群相互作用的扩展提供了一种方法来系统地提高模型的准确性，它是简单的概括这一过程的多组分系统。浓度相关的原子间相互作用势可以建立在几乎任何类型的纯元素势的基础上，包括嵌入原子法（EAM），修正的EAM，键序和Stillinger-Weber型势。一般来说，总能量中的成分依赖的N体项导致显式的（N + 1）体力，这可能使它们在计算上昂贵。我们提出了一种算法，克服了这个问题，可以加快计算的组成相关的对电位的力量，以这样一种方式，使他们计算可比的效率和缩放行为的标准EAM潜力。我们还讨论了Monte Carlo模拟的实现。最后，我们举例回顾了Fe-Cr体系的组分依赖EAM模型。
We propose a simple scheme to construct composition-dependent interatomic potentials for multicomponent systems that, when superposed onto the potentials for the pure elements, can reproduce not only the heat of mixing of the solid solution in the entire concentration range but also the energetics of a wider range of configurations including intermetallic phases. We show that an expansion in cluster interactions provides a way to systematically increase the accuracy of the model, and that it is straightforward to generalise this procedure to multicomponent systems. Concentration-dependent interatomic potentials can be built upon almost any type of potential for the pure elements including embedded atom method (EAM), modified EAM, bond-order, and Stillinger–Weber type potentials. In general, composition-dependent N-body terms in the total energy lead to explicit (N + 1)-body forces, which potentially render them computationally expensive. We present an algorithm that overcomes this problem and that can speed up the calculation of the forces for composition-dependent pair potentials in such a way as to make them computationally comparable in efficiency and scaling behaviour to standard EAM potentials. We also discuss the implementation in Monte Carlo simulations. Finally, we exemplarily review the composition-dependent EAM model for the Fe–Cr system.