( 北京理工大學 國家高技術綠色材料發(fā)展中心， 北京 100081)
摘 要: 采用總體能量-平面波贗勢方法， 并結合超軟贗勢技術， 計算了金屬La、 Ni及合金LaNi5的總體能量、 能帶結構、 電子態(tài)密度以及Mulliken布居值。 根據計算結果， 分析了La、 Ni和LaNi5的電子結構。 結果表明： 形成合金后費米面能量位置漂移， 介于Ni和La的費米面之間， 費米面上主要是Ni 3d電子； 費米面附近導帶的電子結構變化較大； 合金中La和Ni間存在電子轉移， 形成了弱的La—Ni鍵， 且?guī)Р糠蛛x子性； 與純金屬相比， 形成合金后La的穩(wěn)定性增強， 而Ni的穩(wěn)定性減弱。 計算了LaNi5的理論生成熱， 結果能較好地符合實驗值。
關鍵字: LaNi5; 總體能量; 生成熱; 電子結構
（ 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
