Abstract: Using density functional theory associated with B3LYP method with 6-31G* and 6-311＋G(3df) basis sets, the optimization of the geometries and electronic structures and the calculation of frequencies for C_nB^δ(δ=0,±1; n=1～6) clusters have been carried out. In addition, the detachment energy ,adiabatic electron affinities of CnB and energy gap of C_nB^δ(δ=0, ±1) were obtained. The results show that the ground state structures of C_nB^－(n=1～6) clusters are linear as C_n clusters due to their isoelectrons. For C_nB (n=1～6) clusters, the ground state structure of C₂B is asymmetric triangle and C₆B is C_2v symmetry planar monocycle, while the other clusters are linear.C₂B^＋ ,C₃B^＋and C₆B^＋ are C_2v symmetry in C_nB＋(n=1～6) clusters. From the geometrical parameters and vibrational frequencies of boron-carbon clusters from 6-311＋G(3df) and 6-31G* basis sets, it was found that the B3LYP functional is less sensitive to the selection of the basis set in investigating the boron-carbon clusters. The photoelectron spectrum of C_nB(n=1～6) clusters indicates that C₄B is easy to accept one electron and difficult to lose one electron, which is in good agreement with the experimental result.

Key words: Carbon boron clusters, Density functional theory, Stucture and stability