Abstract We have investigated the structural, mechanical, electronic, thermodynamics, and superconducting properties of new ternary equiatomic pnictides LaIrP and LaIrAs superconductors using first-principles density functional theory (DFT) calculations for the first time. Theoretical Vicker's hardness and chemical bonding have also been estimated for these compounds. All the investigated results are compared with available experimental data. The evaluated structural parameters are found to be in good agreement with the experimental data. The single and polycrystalline elastic moduli have been calculated and the mechanical stabilities of LaIrP and LaIrAs have been theoretically confirmed. The ductility nature appears from the values of the Pugh ratio and Poisson's ratio. The shear modulus and Young's modulus increase in the case of As substitution by P in LaIrAs. The bulk modulus increases when P substitution by As in LaIrP. The evaluated elastic moduli show that both superconductors are anisotropic material. The valence band and conduction band are overlapped in the band structure and the electronic band structure shows that both materials behave metallic nature. The most effective contribution to the density of states comes from Ir-5d states at the Fermi level. The chemical bonding of LaIrP and LaIrAs denotes the excessively anisotropic combination between ionic, covalent, and metallic interactions. The Fermi surface created with hole-type and electron-type sheets. The theoretical Vicker's hardness shows that the LaIrP material is harder than LaIrAs. The Debye temperature 227.92 K (LaIrP) and 210.56 K (LaIrAs) are calculated by using present elastic constants data. The calculated theoretical superconducting transition temperatures are 6.43 K and 5.75 K for LaIrP and LaIrAs superconductors. All superconducting phenomena indicate the phonon-mediated medium couple BCS superconductor.

中文翻译：

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三元超导体 LaIrP (P = P, As) 的电子、弹性、振动和超导特性：来自 DFT 的见解

摘要 我们首次使用第一性原理密度泛函理论 (DFT) 计算研究了新型三元等原子 pnictides LaIrP 和 LaIrAs 超导体的结构、机械、电子、热力学和超导特性。还估计了这些化合物的理论维氏硬度和化学键。所有研究结果都与可用的实验数据进行了比较。发现评估的结构参数与实验数据非常吻合。计算了单晶和多晶弹性模量，理论上证实了 LaIrP 和 LaIrAs 的机械稳定性。从 Pugh 比和泊松比的值中可以看出延展性。剪切模量和杨氏' 在 LaIrAs 中 As 被 P 取代的情况下，s 模量增加。当 LaIrP 中的 P 被 As 取代时，体积模量增加。评估的弹性模量表明两种超导体都是各向异性材料。价带和导带在能带结构中重叠，电子能带结构表明两种材料都具有金属性质。对态密度最有效的贡献来自费米能级的 Ir-5d 态。LaIrP 和 LaIrAs 的化学键合表示离子、共价和金属相互作用之间过度的各向异性组合。用空穴型和电子型片创建的费米面。理论维氏硬度表明，LaIrP 材料比 LaIrAs 更硬。德拜温度 227.92 K (LaIrP) 和 210。56 K (LaIrAs) 是通过使用现有的弹性常数数据计算得出的。对于 LaIrP 和 LaIrAs 超导体，计算出的理论超导转变温度为 6.43 K 和 5.75 K。所有超导现象都表明声子介导的介质偶 BCS 超导体。