原子团簇N8的分子模型设计与量子化学计算

根据N5^ 和N3^-两种离子的存在，预测可能存在原子团簇N8，使用分子模拟软件设计出20种N8的同分异构体，然后采用量子化学从头算方法在HF／STO-3G理论水平下对各个分子进行了全构型优化、热力学计算和谐振频率分析，最后讨论了N8的实验合成路线．计算结果表明，有12种同分异构体可稳定存在，其中平面双五元环结构(D2h)最为稳定,能量分析表明，可稳定存在结构的N8含有比4个N2高得多的能量，如果能够合成出N8，将会成为潜在的绿色高能量密度材料。

Molecular Model Design and Quantum Chemistry Calculation of Cluster N8

The existence of cluster N_8 was predicted according to the existence of N_5 + and N_3 -. Twenty N_8 isomers were then designed by using the molecular simulation software. The full geometry optimization,thermodynamics calculation and harmonic vibration frequency analysis of these twenty N_8 molecules were performed at the HF/STO-3G level with the ab initio method of quantum chemistry. The synthesis routes of N_8 in experiments were finally discussed. The calculated results show that twelve of the twenty N_8 isomers can stably exit,and that the planar double five-member ring form of N_8 with D_ 2h symmetry is the most stable. Energy analysis result indicates that a N_8 molecule with a stable structure contains much higher energy than four N_2 molecules,which means N_8 is a potential green material with high energy density.