( 1. 四川大学 原子分子物理研究所，成都 610065;
2. 中国工程物理研究院 物理与化学研究所， 绵阳 621900)
摘 要: 从密度泛函理论为基础的第一性原理出发， 运用全势能线性缀加平面波方法， 对LaNi5Hx(x=3, 4, 5)进行了建模研究， 经过优化得到稳定的晶体结构， 从理论上验证其存在性， 并计算给出了它们的电子密度以及状态密度图。 结果表明： 在几种模型中， H原子最终稳定地排布在基平面（12n位）和中间面（6m位）上， 并且趋向晶胞的同一侧； 随着H原子的增多， 晶胞参数a值（0.527 3～0.5 310 nm）增大相对较小， 而c值(0.407 5～0.416 5 nm)有较大的增加， 与实验结果一致； 并且La与Ni的相互作用进一步减弱。
关键字: LaNi5Hx； 镧基储氢材料； 第一性原理； 全势能线性缀加平面波方法
中图分类号: TG 139.7
hydrogen storage process
（1. Institute of Atomic and Molecular Physics, Sichuan University,
Chengdu 610065, China;
2. Institute of Nuclear Physics and Chemistry,
Chinese Academy of Engineering Physics, Mianyang 621900, China）
Abstract: The density functional GGA method and the full-potential linearized augmented plane wave were used to optimize the cell and internal parameters of hydrides LaNi5Hx(x=3, 4, 5). The equilibrium structure, density of state and charge density were worked out. The results indicate that hydrogen atoms are distributed in the basal plane（12n site） and the middle plane (6m site) at end and tend to lie in the same side. With the increase of the number of hydrogen atom in the alloy, a value of crystal cell parameter （0.527 3-0.531 0 nm）increases comparatively less whereas c value (0.407 5-0.416 5 nm) increases comparatively more, which agrees exactly with the experiment; moreover the interaction between La atom and Ni atom bring down further.
Key words: LaNi5Hx; La-based hydrogen storage material; first principle; full-potential linearized augmented plane wave (FLAPW)
