Abstract This article deals with the structural, elastic, thermodynamic, and electronic properties of Half-Heusler compounds; YNiPn (Pn = As, Sb, and Bi). The computations are carried out using the pseudopotential plane-wave method within the generalized gradient approximation (GGA). We have noticed the structural stability in the F-43m phase and lattice constants are well matched with experimental results. The elastic, thermodynamic, and major electronic properties are reported for the first time in these compounds. We have derived the bulk, shear, and Young’s moduli of elasticity from the knowledge of elastic constants along with the discussion of mechanical stability and strength of YNiPn. The Cauchy pressure and Pugh’s ratio emphasizes ductile nature. From the knowledge of elastic properties, it is observed that the Debye temperature and sound velocities are decreasing from As to Bi. The electronic properties are discussed in terms of band profile, the density of states (DOS), charge density plot, and Fermi surfaces. The electronic band structure and DOS clarify that YNiPn compounds are indirect narrow bandgap semiconductors. The origins of the bandgap in these compounds are interpreted. The charge density plot projects the strong covalent bonding between Ni and Pn atoms while an ionic bonding between Y and Pn atoms. The thermodynamic variables like cell volume, bulk modulus, specific heat, Debye temperature, entropy, Gruneisen parameter, and thermal expansion coefficients have also been analyzed under high pressure and temperature as they are of great technological importance. These compounds are found as potential candidates for thermoelectric materials.

中文翻译：

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半赫斯勒化合物的结构、弹性、电子和热力学性质的第一性原理研究；YNiPn（Pn=As、Sb 和 Bi）

摘要 本文讨论了半赫斯勒化合物的结构、弹性、热力学和电子特性；YNiPn（Pn = As、Sb 和 Bi）。使用广义梯度近似 (GGA) 中的赝势平面波方法进行计算。我们注意到 F-43m 相的结构稳定性和晶格常数与实验结果很好地匹配。首次报道了这些化合物的弹性、热力学和主要电子特性。我们从弹性常数的知识以及 YNiPn 的机械稳定性和强度的讨论中推导出了体积、剪切和杨氏弹性模量。柯西压力和普格比强调延展性。根据弹性性质的知识，观察到德拜温度和声速从 As 降低到 Bi。根据能带轮廓、态密度 (DOS)、电荷密度图和费米面讨论电子特性。电子能带结构和 DOS 表明 YNiPn 化合物是间接窄带隙半导体。解释了这些化合物中带隙的起源。电荷密度图显示了 Ni 和 Pn 原子之间的强共价键，而 Y 和 Pn 原子之间的离子键。热力学变量，如细胞体积、体积模量、比热、德拜温度、熵、格鲁尼森参数和热膨胀系数，也在高压和高温下进行了分析，因为它们具有重要的技术意义。