The A15-type conventional superconductor Nb₃Al alloys have been widely studied because of their high-performance superconductivity, which is generally considered a β-W₃O-type structure with space group $\mathrm{Pm}\bar{3}\mathrm{n}$ at ambient pressure. In this study, four new crystalline phases of Nb₃Al with space groups C2/m, I4/mmm, Pmmm and $\mathrm{Pm}\bar{3}\mathrm{m}$ were predicted using the particle swarm optimisation method. The mechanical parameters of the predicted phases under high pressure were also obtained using first-principle calculations. The competing enthalpies revealed that A15-type Nb₃Al undergoes a phase transition from $\mathrm{Pm}\bar{3}\mathrm{n}$ to I4/mmm at 20 GPa pressure and then to Pmmm at 118 GPa. Although the Pmmm phase became mechanically unstable at 37.6 GPa via the Born–Huang criterion, mechanical analysis of the I4/mmm structure exhibited a greater toughness and superior mechanical properties than that of A15 Nb₃Al. Phonon and Debye calculations also proved I4/mmm to be thermodynamically and dynamically stable at ambient pressures and low temperatures. The energetically favourable phases of Nb₃Al that were discovered provided a more theoretical mechanistic basis for its preparation and development.

A15型常规超导体Nb ₃ Al合金由于其高性能的超导性而被广泛研究，通常被认为是具有空间群的β - W ₃ O型结构$\mathrm{下午}\bar{3}\mathrm{ñ}$在环境压力下。在这项研究中，Nb ₃ Al的四个新晶相的空间群为C2 / m，I4 / mmm，Pmmm和$\mathrm{下午}\bar{3}\mathrm{米}$使用粒子群优化方法进行预测。还使用第一性原理计算获得了高压下预测相的机械参数。竞争的焓表明，A15型Nb ₃ Al经历了从$\mathrm{下午}\bar{3}\mathrm{ñ}$在20 GPa压力下达到I4 / mmm，然后在118 GPa下达到Pmmm。尽管根据Born-Huang准则，Pmmm相在37.6 GPa时机械不稳定，但与A15 Nb ₃ Al相比，I4 / mmm结构的力学分析显示出更高的韧性和优异的机械性能。声子和德拜的计算还证明I4 / mm在环境压力和低温下具有热力学和动态稳定性。发现的Nb ₃ Al在能量上有利的相为其制备和开发提供了更理论上的机械基础。