( 北京理工大学 国家高技术绿色材料发展中心， 北京 100081)
摘 要: 采用总体能量-平面波赝势方法， 并结合超软赝势技术， 计算了金属La、 Ni及合金LaNi5的总体能量、 能带结构、 电子态密度以及Mulliken布居值。 根据计算结果， 分析了La、 Ni和LaNi5的电子结构。 结果表明： 形成合金后费米面能量位置漂移， 介于Ni和La的费米面之间， 费米面上主要是Ni 3d电子； 费米面附近导带的电子结构变化较大； 合金中La和Ni间存在电子转移， 形成了弱的La—Ni键， 且带部分离子性； 与纯金属相比， 形成合金后La的稳定性增强， 而Ni的稳定性减弱。 计算了LaNi5的理论生成热， 结果能较好地符合实验值。
关键字: LaNi5; 总体能量; 生成热; 电子结构
（ National Development Center of Hi-Tech Green Materials,
Beijing Institute of Technology, Beijing 100081, China）
Abstract: The calculations of total energy, energy band structure, electronic density of states and Mulliken population of LaNi5 were performed by adopting the method of total energy combined with ultra-soft Pseudopotential technology. The change of the electronic structure in the formation of LaNi5 was analyzed according to the calculations. The results show that the Fermi level shifts toward the position between those of La and Ni. Ni 3d electrons mainly contribute to the states of density at Fermi level. The electronic structure of conduction band near Fermi level is changed markedly, especially for Ni. In alloys, electron transfer exists between La and Ni, thus weakly bond is formed with partly of ionicity. The stability of La increases and that of Ni decreases in LaNi5 compared with the pure metal. The theoretical formation heat of LaNi5 is obtained and accords well with the experimental value.
Key words: LaNi5; total energy; formation heat; electronic structure
