Nanocrystals of group 5 tetradymites M₂X₃ (where M = Bi and Sb, X = Se and Te) are of high technological relevance in modern topological nanoelectronics. However, there is a current lack of a systematic understanding to predict the preferred nanocrystal morphology in experiments where commonly-used equilibrium thermodynamic models appear to fail. In this work, using first-principles DFT calculations with a rationally-extended ab initio atomistic thermodynamics approach coupled to implicit solvation models and Gibbs–Wulff shape constructions, we demonstrate that this absence of predictive power stems from the limitation of equilibrium thermodynamics. By re-tracing and carefully addressing with a more realistic chemical potential definition, we illustrate this shortcoming can be overcome and afford a more rational route to size-engineer and shape-design highly-functional group 5 tetradymite nanoparticles for targeted applications.

中文翻译：

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超越平衡晶体形状：重新追踪第 5 族四镱纳米晶体的形态演变

第 5 族 tetradymites M ₂ X _{3 的}纳米晶体（其中 M = Bi 和 Sb，X = Se 和 Te）在现代拓扑纳米电子学中具有很高的技术相关性。然而，目前缺乏系统的理解来预测实验中常用的平衡热力学模型似乎失败的首选纳米晶体形态。在这项工作中，使用具有合理扩展的ab initio 的第一性原理 DFT 计算结合隐式溶剂化模型和 Gibbs-Wulff 形状构造的原子热力学方法，我们证明了这种预测能力的缺乏源于平衡热力学的局限性。通过使用更现实的化学势定义重新追踪和仔细解决，我们说明了这一缺点可以克服，并提供更合理的途径来为目标应用进行尺寸工程和形状设计高功能第 5 族四镱纳米粒子。