A theoretical study of structures and chemical bonding of mixed clusters X3Y3H6 (X = B, Al, Ga, In Y = N, P, As, Sb)

Abstract

By using density functional theory (DFT) and MP2 method, we optimized the plane-form, chair-form, and boat-form of X3Y3H6 (X=B, Al, Ga, In Y=N, P, As, Sb) clusters. The results indicate that the plane form of X3N3H6 clusters are more stable than chair and boat form. For other considered clusters, the chair form is more stable than plane and boat form. The difference in energy between chair form and boat form are no more than 0.2eV. B3N3H6 cluster is the most stable among considered clusters by calculating binding energy, and the stability of In3Sb3H6 cluster is the lowest. In addition, the binding energy of B3N3H6 cluster is 5.009eV, and only 0.74eV lower than that of C6H6(5.749eV). By using AdNDP method, we found that B3N3H6 cluster has six π-electrons. According to Huckel’s 4n+2 rule, it should be π aromatic, which also explains the stability of planar structure for B3N3H6 cluster. Other considered clusters are apt to chair form owing to pseudo–Jahn–Teller effect.