Hydrogen can be utilized as an energy source; therefore, hydrogen storage has received the most appealing examination interest in recent years. The investigations of hydrogen storage applications center fundamentally around the examination of hydrogen capacity abilities of recently presented compounds. XSrH₃ (X = K and Rb) compounds have been examined by density functional theory (DFT) calculations to uncover their different characteristics, as well as hydrogen capacity properties, for the first time. Studied compounds are optimized in the cubic phase, and optimized lattice constants are obtained as 4.77 and 4.99 Å for KSrH₃ and RbSrH₃, respectively. These hydrides have shown negative values of formation enthalpies as they are stable thermodynamically. XSrH₃ might be used in hydrogen storage applications because of high gravimetric hydrogen storage densities, which are 2.33 and 1.71 wt% for KSrH₃ and RbSrH₃, respectively. Moreover, electronic properties confirm the semiconductor nature of these compounds having indirect band gaps of values 1.41 and 1.23 eV for KSrH₃ and RbSrH₃, respectively. In addition, mechanical properties from elastic constants such as Young modulus and Pugh's ratio, also have been investigated, and these compounds were found to satisfy born stability conditions. Furthermore, Pugh's ratio and Cauchy pressure show that these hydrides have a brittle nature. Furthermore, thermodynamic properties such as entropy and Debye temperature have been examined using the quasiharmonic Debye model for different temperatures and pressures.

中文翻译：

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XSrH3（X = K和Rb）钙钛矿型氢化物用于储氢的第一性原理研究

氢气可以用作能源；因此，储氢近年来受到了最有吸引力的检查兴趣。氢存储应用的研究主要围绕检查最近提出的化合物的氢容量能力。XSrH ₃（X = K和Rb）化合物已通过密度泛函理论（DFT）计算进行了检验，以首次发现它们的不同特性以及氢容量特性。在立方相中优化了所研究的化合物，对于KSrH ₃和RbSrH _3而言，优化的晶格常数分别为4.77和4.99Å 。这些氢化物在热力学上稳定，显示出负的地层焓。S₃可能在由于高重量储氢密度，这是2.33和1.71 KSrH重量％的储氢应用中使用₃和RbSrH ₃，分别。此外，电子性质证实了这些化合物的半导体性质，其KSrH ₃和RbSrH _3的间接带隙分别为1.41和1.23 eV， 分别。另外，还研究了由弹性常数例如杨氏模量和普格比（Pugh's ratio）引起的机械性能，发现这些化合物满足固有的稳定性条件。此外，Pugh比和柯西压力表明这些氢化物具有脆性。此外，对于不同的温度和压力，使用准谐波德拜模型检查了诸如熵和德拜温度的热力学性质。