A study of the bonding and electronic properties of intermetallics under pressure is crucial in the design and development of novel materials for useful applications. These properties are largely controlled by the underlying crystal structures. Here we investigated the high-pressure structural behavior of PtIn₂ using crystal structure search calculations, which efficiently combine evolutionary algorithms and state-of-the-art density functional theory. Three new crystal structures, namely, Fe₂B-type (I4/mcm, Z = 2), cotunnite-type (Pnma, Z = 4), and monoclinic (C2/m, Z = 2), are proposed at about 9.4, 13.5, and 47.5 GPa, respectively. With pressure, the covalent character of the Pt–In pair interaction is found to increase because of enhancement of spd hybridization, and structural transitions are rationalized in terms of the covalency increase.

中文翻译：

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PtIn ₂在高压下的结构相变：理论研究

对金属间化合物在压力下的键合和电子性能的研究对于设计和开发适用于应用的新型材料至关重要。这些性质在很大程度上由下面的晶体结构控制。在这里，我们使用晶体结构搜索计算研究了PtIn ₂的高压结构行为，该算法有效地结合了进化算法和最新的密度泛函理论。三种新的晶体结构，分别是Fe ₂ B型（I 4 / mcm，Z = 2），钙锌矿型（Pnma，Z = 4）和单斜晶型（C 2 / m，Z= 2），建议分别约为9.4、13.5和47.5 GPa。在压力作用下，由于spd杂交的增强，发现Pt-In对相互作用的共价特性增加，并且结构上的过渡因共价增加而合理化。