AbstractHere we studied the geometric, electronic, and vibrational properties of the BxNy(x + y= 6) clusters through ab initio density functional theory calculations. Additional coupled‐cluster theory restricted to single, double, and noniterative triple excitation single‐point calculations are performed for clusters close in energy (≤0.5 eV). Our results show that planar ring structures (except the B6) have deemed to have lower energies as compared with three‐dimensional clusters. A greater stability of the stoichiometric cluster B3N3is predicted, followed by the B4N2and B2N4clusters. The BN5cluster is deemed to dissociate in an N2+ BN3channel. The B3N3cluster is suggested as an initial step in the growth process of the hexagonal boron nitride (BN). Some available experimental results on these six‐atom BN clusters are considered and partly explained. © 2003 Wiley Periodicals, Inc. Int J Quantum Chem 95: 329–335, 2003