Efficient determination of alloy ground-state structures
Efficient determination of alloy ground-state structures
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DOI：
10.1103/physrevb.90.174104
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发表时间：
2014-11-10
影响因子：
3.7
通讯作者：
Tanaka, Isao
中科院分区：
文献类型：
--
作者：
Seko, Atsuto;Shitara, Kazuki;Tanaka, Isao
提出了一种基于团簇展开的精确计算合金基态结构的有效方法。在这种方法中，在没有任何关于能量的信息的情况下，得到了少量的候选基态结构。为了生成候选结构，我们使用了由所有可能结构的相关函数构造的凸壳，并使用了一种有效的算法。这种方法不仅适用于简单格，也适用于复杂格。首先，我们计算了具有四种简单晶格的二元合金的凸壳。然后我们讨论了顶点上的结构。为了检验这种方法的准确性，我们对Ag-Au合金进行了一系列密度泛函理论计算和团簇展开，并比较了顶点结构的形成能和所有可能结构的形成能。作为应用，对金属间化合物CuAu、CuAg、CuPd、AuAg、AuPd、AgPd、MoTa、MoW和Taw的基态结构进行了类似的评估。最后，给出了不同阳离子排列方式下的能量分布，长程相互作用是准确描述其能级的关键。
We propose an efficient approach to accurately finding the ground-state structures in alloys based on the cluster expansion method. In this approach, a small number of candidate ground-state structures are obtained without any information regarding the energy. To generate the candidates, we employ the convex hull constructed from the correlation functions of all possible structures by using an efficient algorithm. This approach is applicable to not only simple lattices, but also complex lattices. First, we evaluate the convex hulls for binary alloys with four types of simple lattice. Then we discuss the structures on the vertices. To examine the accuracy of this approach, we perform a set of density functional theory calculations and the cluster expansion for the Ag-Au alloy and compare the formation energies of the vertex structures with those of all possible structures. As applications, the ground-state structures of the intermetallic compounds CuAu, CuAg, CuPd, AuAg, AuPd, AgPd, MoTa, MoW, and TaW are similarly evaluated. Finally, the energy distribution is obtained for different cation arrangements in the MgAl2O4 spinel, for which long-range interactions are essential for the accurate description of its energetics.