Systematic study of small BN clusters

We performed a systematic investigation of the small BxNy (x+y less than or equal to 6) clusters using the ab initio Hartree-Fock scheme plus second-o rder perturbation theory. The nature of the potential energy surface extrem a are analyzed through analytical total energy second derivatives. Ionizati on potentials, binding energies and the stability against some possible rea ction mechanisms are calculated. Based on these results we propose that the growing process for these clusters is mainly due to the successive incorpo ration of BN molecules. A discussion of some mass spectrometry experimental results is also presented.