Abstract This study reports a theoretical examination of the structural, elastic, mechanical, electronic, phonon and electron–phonon interaction properties of the body-centered orthorhombic structure of NbPS by using the generalized gradient approximation of the density functional theory and the planewave ab initio pseudopotential method. An analysis of the elastic and mechanical properties reveals ductile nature of this compound. The electronic density of states at the Fermi energy is heavily contributed by d orbitals, revealing a more active role for transition metal Nb atoms in determining the lattice dynamical as well as the superconducting properties of NbPS. The phonon spectrum is characterized by anomalies in the lowest acoustic and lowest optical branches which are dominated by the vibrations of Nb atoms. The characteristic features in the electron and phonon spectra clearly suggest that the lowest branches of acoustic and optical nature are more involved in the process of scattering of electrons than the remaining ones due to their phonon anomalies and the significant existence of Nb d electrons at the Fermi level. From the integration of the Eliashberg spectral function, we obtain a value of average electron–phonon coupling constant λ = 1.07, confirming strong interaction between electrons and phonons. The computed value of superconducting critical temperature T c = 13.7 K harmonizes very well with the experimentally reported value of 13.0 K.

中文翻译：

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NbPS 物理性质和超导性的第一性原理研究

摘要 本研究报告了使用密度泛函理论的广义梯度近似和平面波从头算赝势对 NbPS 体心正交结构的结构、弹性、机械、电子、声子和电子-声子相互作用特性的理论研究。方法。对弹性和机械性能的分析揭示了这种化合物的延展性。费米能级的电子密度主要由 d 轨道贡献，这表明过渡金属 Nb 原子在决定 NbPS 的晶格动力学和超导特性方面发挥着更积极的作用。声子谱的特点是在最低声波和最低光波分支中出现异常，这些分支以 Nb 原子的振动为主。电子和声子光谱的特征清楚地表明，由于声子异常和费米处 Nb d 电子的显着存在，声学和光学性质的最低分支比其余分支更多地参与电子散射过程。等级。从 Eliashberg 谱函数的积分中，我们获得了平均电子 - 声子耦合常数 λ = 1.07 的值，证实了电子和声子之间的强相互作用。超导临界温度 T c = 13.7 K 的计算值与实验报告的值 13.0 K 非常吻合。