Evolutionary method for predicting surface reconstructions with variable stoichiometry
Evolutionary method for predicting surface reconstructions with variable stoichiometry
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DOI：
10.1103/physrevb.87.195317
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发表时间：
2013-05-28
影响因子：
3.7
通讯作者：
Allen, Philip B.
中科院分区：
文献类型：
--
作者：
Zhu, Qiang;Li, Li;Allen, Philip B.
我们提出了一个专门设计的进化算法的表面重建的预测。这种技术允许人们自动探索稳定和低能量的亚稳态配置与可变的表面原子和可变的表面晶胞通过整个化学势范围。进化搜索的力量证明了钻石2 × 1（100）和2 × 1（111）表面重建与固定数量的表面原子和固定的细胞大小的有效识别。随着表面晶胞的进一步变化，我们研究了MgO（111）极面的重构。实验已经检测到氧三聚体（臭氧）基序[Plass等人，物理修订信函81，4891（1998）]。我们预测这个主题的另一个版本，可以在极端富氧条件下稳定。最后，我们进行了一个复杂的三元系统的可变化学计量搜索：半极性GaN（10（1）在bar 1）与和没有吸附氧。该搜索产生了基于N-3三聚体的违反直觉的重建。这些例子表明，一个自动化的计划，探索表面的能量景观将提高我们的理解表面重建。本文提出的方法可普遍应用于二元和多元体系。
We present a specially designed evolutionary algorithm for the prediction of surface reconstructions. This technique allows one to automatically explore stable and low-energy metastable configurations with variable surface atoms and variable surface unit cells through the whole chemical potential range. The power of evolutionary search is demonstrated by the efficient identification of diamond 2 x 1 (100) and 2 x 1 (111) surface reconstructions with a fixed number of surface atoms and a fixed cell size. With further variation of surface unit cells, we study the reconstructions of the polar surface MgO (111). Experiment has detected an oxygen trimer (ozone) motif [Plass et al., Phys. Rev. Lett. 81, 4891 (1998)]. We predict another version of this motif which can be thermodynamically stable in extreme oxygen-rich conditions. Finally, we perform a variable stoichiometry search for a complex ternary system: semipolar GaN (10 (1) over bar1) with and without adsorbed oxygen. The search yields a counterintuitive reconstruction based on N-3 trimers. These examples demonstrate that an automated scheme to explore the energy landscape of surfaces will improve our understanding of surface reconstructions. The method presented in this paper can be generally applied to binary and multicomponent systems.