The structures of(BN)n(n. = l~16) clusters were studied by using Hartree-Fock (HF), B3LYP of density functional theory (DFT) and second order perturbation theory MP2 method with basis set of 6-31G(d). The geometries, natural bond orbital (NBO), electron structures, vibrational spectra, binding energies, nucleus independent chemical shirts (NICS) and energy secondaiy differences of ring and cage structures were discussed at the same level. The relationship between structure and stability was obtained. The results obtained from these three theoretical methods were also compared.

Key words: DFT, CLUSTER COMPOUND, BORON NITRIDE, CHEMICAL SHIFT