A Parallel Study on (BN)_n and (HAlNH)_n (n=11-22) Clusters: Geometry and Stability

A parallel study on (BN)_n and (HAlNH)_n (n=11-22) clusters is presented herein with ab initio HF/6-31G* method. Two types of structures, i.e. cage-like and needle-shaped, are constructed. The calculated results indicate that the classical cage-like geometry is energetically more favourable for (BN)_n while the needle-shaped (HAlNH)_n structures are more stable than their cage-like counterparts. It is suggested that the nanostructures with higher structural similarity to the corresponding bulk phases possess greater stability. This idea leads to the viable way to intercept segment from bulk materials to construct models for theoretical study of complex nanostructures.