Based on the first-principles calculations, the stable structures of Fe_xM_1-x (M = Y, La) binary alloy have been determined according to the formation enthalpy, and the calculated binding energy of hydrides as a function of chemical potential show that the YFe₂H_4.5 is stable. The thermodynamic stabilities of target alloys and hydrides at various temperatures have further been confirmed using the quasi harmonic approximation in lattice vibration theory. The nudged elastic band method (NEB) is used to investigate the diffusion of hydrogen atoms at different interstitials. The charge density distribution of YFe₂ and YFe₂H₅ has been analyzed to demonstrate the structural stability and the dehydrogenation process. The elastic modulus of YFe₂, YFe₂H₅, LaFe₂ and LaFe₂H₅ will decrease as the temperature increases, with a weaker anisotropy in the Y–Fe system than that in the La–Fe system.

基于第一性原理计算，根据形成焓确定了 Fe _x M _1-x (M = Y, La) 二元合金的稳定结构，计算出的氢化物结合能与化学势的函数关系表明YFe ₂ H _4.5是稳定的。目标合金和氢化物在不同温度下的热力学稳定性已使用晶格振动理论中的准谐波近似得到进一步证实。轻推弹力带法 (NEB) 用于研究氢原子在不同间隙中的扩散。YFe ₂和YFe ₂ H ₅的电荷密度分布已被分析以证明结构稳定性和脱氢过程。YFe ₂、YFe ₂ H ₅、LaFe ₂和LaFe ₂ H ₅的弹性模量随着温度的升高而降低，Y-Fe 系统的各向异性比La-Fe 系统弱。