Cun(n=2-20)团簇的稳定性和电子性质的密度泛函研究

采用密度泛函理论中的PW91/DNP方法研究了Cun(n=2~20)团簇的稳定性和电子性质。结果表明：在n=2~8区间，平均结合能曲线几乎呈现线性增长；在n=9~20区间，平均结合能曲线相对较平缓。Cun(n=4, 7, 8, 17)团簇相对较稳定。Cun(n=2, 4, 8, 13, 19)团簇的能隙值相对较大，化学活性较弱。在n=2~20区间，垂直电离能略微大于绝热电离能, 绝热亲和能略微大于垂直亲和能。在n=2~9区间，电离能曲线呈现出显著的奇—偶振荡效应，即n为偶数团簇的电离能比临近奇数团簇的要大；亲和能曲线呈现出同电离能曲线相反的奇—偶振荡效应。

Density functional theory study on the stability and electronic properties of Cun(n=2-20) clusters

The stability and electronic properties of Cun(n=2~20) clusters were studied by using the method of PW91/DNP in density functional theory. The results show that the average binding energy curve increases linearly with cluster size n = 2 ~ 8, it becomes more flat versus cluster size n = 9 ~ 20. Cun(n=4, 7, 8, 17) clusters are more stable than the others. The energy gaps of Cun(n=2, 4, 8, 13, 19) clusters are larger than the others, so their chemical activity is also weaker than the others. The vertical ionization energy is slightly greater than the adiabatic ionization energy and the adiabatic affinity energy is slightly greater than the vertical affinity energy between the cluster size n=2~20. The ionization energy curve shows a significant odd-even oscillation effect, namely the ionization energy of the cluster whose size is even number is larger than that of the near cluster whose size is odd number, and the affinity energy curve also shows a significant odd-even oscillation effect but which is opposite to that of the ionization energy curve.