Ga_nN_3(n=1～8)团簇几何结构及光电子能谱的研究

Structures and Photoelectron Energy Spectroscopy about Ga_nN_3(n=1～8) Clusters

用密度泛函理论的B3LYP方法在6-31G*的水平上,对GanN3(n=1～8)团簇的结构进行优化,并对体系的成键特性、光电子能谱及稳定性进行了计算与分析,得到了GanN3(n=1～8)团簇的最稳定结构.结果表明,当n≤5时,其基态几何结构为平面结构,N-N键在这些团簇的形成过程中起着决定性的作用;当n≥6时,其基态几何结构为立体结构,Ga-N键起主导作用;在所研究的团簇中,Ga4N3、Ga7N3的基态结构最稳定;随着n值的增大,平均极化率逐渐增强;通过对光电子能谱的分析,得到Ga-N键的振动频率与六方晶系纤锌矿结构GaN的光学声子峰值相近.

The B3LYP method of Density Functional Theory（DFT） is used to optimize geometry configuration of GanN3（n=1-8） clusters at the level of 6-31G＊.The bond properties,photoelectron energy spectroscopy and stability are calculated and analyzed,and the most stable structures are obtained finally.The results show that there is a transition from planar to spacial structures at n=5 with increasing cluster size,and N-N bonds are more stable.The strong Ga-N bonds play an important role in GanN3（n=6-8）.Among the GanN3（n=1-8） clusters,Ga4N3,Ga7N3are more stable｜ Average polarizabilities are increased as the n value increases.The vibrational frequencies of Ga-N bond are close to the peaks of the phonon vibration modes of the wurtzite structure GaN by analyzed the photoelectron energy spectroscopy.