InnNa和InnNa+(n=2-8)的团簇结构和电子性质

在密度泛函理论B3LYP水平上, 对InnNa和InnNa+(n=2-8)团簇进行了结构优化和振动频率计算. 计算结果表明, InnNa(n=2、3、4、6)最稳定结构中的对称性分别为C2v、C3v、C4v和C2v, 而InnNa(n=5、7、8)的最稳定结构的对称性为C1点群. 从InnNa(n=4-8)的最稳定结构可以看出, Na原子均位于四个In原子形成的四边形面上. 对于InnNa+(n=2-8), 除了In2Na+、In4Na+和In7Na+, 其它结构都与其中性结构相似. 进一步计算InnNa(n=2-8)团簇的平均结合能、能量的二阶差分以及绝热电离能表明, InnNa(n=2-8)团簇能量的二阶差分呈现奇偶交替特征, In4Na和In6Na较其它团簇更为稳定, 而且理论计算得到的绝热电离能和实验结果吻合得很好.

Structure and Electronic Properties of InnNa and InnNa+(n=2-8) Clusters

Structures and vibrational frequencies of InnNa and InnNa+(n=2-8) clusters were investigated with density functional theory at B3LYP level. The results show that the most stable structures of InnNa (n=2,3,4, 6) have C2v, C3v, C4v and C2v symmetry, respectively. The InnNa (n=5, 7, 8) clusters have a C1 point group symmetry. InnNa (n=4-8) clusters have the same character as Na is located within the plane formed by the four In atoms. The most stable structures for InnNa+(n=2-8) clusters are similar to their neutral structures, except for In2Na+, In4Na+ and In7Na+. The average binding energy, second-order difference of energy and adiabatic ionization potentials of InnNa (n=2-8) clusters were calculated at the same theoretical level. We found an odd-even alternative character between the second-order difference of energy and the cluster size. In4Na and In6Na are more stable than the other studied compounds. The calculated adiabatic ionization potentials are in good agreement with experiment values.