(1. 四川大学 原子与分子物理研究所， 成都 610065；
2. 中国工程物理研究院， 绵阳 621900)
摘 要: 在全电子水平上， 基于广义梯度近似密度泛函和全势能线性缀加平面波方法， 计算了不同Al含量LaNi5-xAlx(x=0, 0.5, 1.0)的晶体结构、 能带结构、 状态密度等特征。 对LaNi5的计算表明： GGA Perdew96的计算结果可信， 自旋极化对优化结构和能量的影响不明显； 对LaNi4Al的研究表明Al原子最可能取代3g位的Ni原子； 对LaNi4.5Al0.5的优化结构与实验结果一致。 随着Al含量的升高， 晶胞能量、 费米面能量升高， 如从LaNi5， LaN4.5Al0.5到LaNi4Al， 费米面能量从-10.591、 -10.134 eV升高到-9.441 eV， 而Ef上的态密度和材料对应的低温比热容则急剧下降， 态密度从11.81、 8.86急剧降低到1.61 eV/f.u.。 并计算给出了LaNi4.5Al0.5的能带结构、 状态密度图。
关键字: LaNi4Al； LaNi4.5Al0.5 ; 全势能线性缀加平面波法(FLAPW)
（1. Institute of Atomic and Molecular Physics,
Sichuan University, Chengdu 610065, China;
2. Chinese Academy of Engineering Physics,
Mianyang 621900, China）
Abstract: Based on the generalized gradient approximation (GGA) of density of function and the full potential linearized augmented wave (FLAPW), the equilibrium structure , energy bands and density of states were calculated for LaNi5-xAlx. The results show that, For LaNi5, the calculation by GGA perdew96 is better than those of other methods, and the spin-polarization have no obvious effect on the optimized structure and energy. For LaNi4Al, the result indicates that nickel is most likely substituted by aluminum on the 3g site, and the optimized structure for LaNi4.5Al0.5 exactly agrees with the experimental results. With the increasing content of aluminum, the Fermi energy and density of states sharply decrease in the order from LaNi5 to LaNi4.5Al0.5 and LaNi4Al, the Fermi Energy increases from -10.591, -10.134 eV to -9.441 eV, and the density of states (DOS) of Ef decreases from 11.81, 8.86 to 1.61 eV/f.u.. The energy band structure and density of states for LaNi4.5Al0.5 were firstly calculated.
Key words: LaNi4Al; LaNi4.5Al0.5; electric structure; full-potential linearized augmented plane wave
