Al_mN和Al_mN^+(m=2～9)团簇结构与稳定性的量子化学研究

Quantum Chemical Study on Structure and Stability of Al_mN and Al_mN^+ (m=2～9) Clusters

用密度泛函理论 (DFT)的B3LYP方法 ,在 6 3 11G 水平上对AlmN和AlmN+ (m =2～ 9)团簇的几何构型、电子结构、振动频率等性质进行了理论研究 ,给出了以Alm 团簇作为设计AlmN类结构的母体 ,考虑在不同位置上结合N原子的结构 ,可以较快找到AlmN类团簇基态结构的一种方法 .通过对基态结构的离解能和能量二次差分讨论 ,得到m为奇数的AlmN团簇比m为偶数的稳定 .对基态结构的绝热电离能讨论结果表明 ,只存在Al—N键的Al2 N和Al3 N团簇较稳定 .

The geometric configurations, electronic structures and vibrational frequencies of the Al mN and Al mN+ (m=2～9) clusters were calculated with B3LYP method at 6-311G* level. The calculations show that the ground states of Al mN clusters can be rapidly obtained by adding nitrogen atom to the different positions of Al m clusters. The dissociation energies and secondary energy differences of the ground states reveal that the Al mN clusters with even m are more stable than those with odd m. The analysis of the adiabatic ionization potential of ground state structures shows that the Al 2N and Al 3N clusters are more stable.