The geometric configurations, electronic structures, vibrational frequency and molecular orbital of the Al_mN₂ and Al_mN₂^＋ (m＝1～8) clusters were studied using the B3LYP DFT method at 6-311G* level. The results show that there exist two types of bonding character in the ground state of Al_mN₂ clusters. One is formed through N—N bonds and aluminum atom, and the other is combined with Al_nN (n≤m/2) fragments in virtue of Al or Al—Al bond. The combined structures with Al_nN fragments with even m are more stable than those with odd m from the analysis of the ionization energy.

Key words: Al_mN₂ and Al_mN₂^＋ cluster, density functional theory, structure, stability, ground state