( 1. 四川大學(xué) 原子分子物理研究所，成都 610065;
2. 中國工程物理研究院 物理與化學(xué)研究所， 綿陽 621900)
摘 要: 從密度泛函理論為基礎(chǔ)的第一性原理出發(fā)， 運(yùn)用全勢能線性綴加平面波方法， 對LaNi5Hx(x=3, 4, 5)進(jìn)行了建模研究， 經(jīng)過優(yōu)化得到穩(wěn)定的晶體結(jié)構(gòu)， 從理論上驗證其存在性， 并計算給出了它們的電子密度以及狀態(tài)密度圖。 結(jié)果表明： 在幾種模型中， H原子最終穩(wěn)定地排布在基平面（12n位）和中間面（6m位）上， 并且趨向晶胞的同一側(cè)； 隨著H原子的增多， 晶胞參數(shù)a值（0.527 3～0.5 310 nm）增大相對較小， 而c值(0.407 5～0.416 5 nm)有較大的增加， 與實驗結(jié)果一致； 并且La與Ni的相互作用進(jìn)一步減弱。
關(guān)鍵字: LaNi5Hx； 鑭基儲氫材料； 第一性原理； 全勢能線性綴加平面波方法
中圖分類號: TG 139.7
hydrogen storage process
ZHANG Yun-guang1，ZHU Zheng-he1，CHEN Bo2
（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)
