Density functional theory study on the structure and properties of MgmBn (m=1,2; n=1-4) clusters

Possible geometrical structures and relative stability of Mg-m B-n ( m = 1, 2; n = 1-4) clusters are studied by using the hybrid density functional theory( B3LYP) with 6-31G* basis sets. For the most stable isomers of Mg-m B-n ( m = 1 2; n = 1-4) clusters, the electronic structure, vibrational properties, bond properties, ionization potential, polarizability and hyperpolarizability are analyzed. The calculated results show that most of the optimized Mg-m B-n ( m = 1 2; n = 1-4) clusters have planar structure, the B-B and B-Mg bonds are coexisting in the cluster, but the Mg-Mg bonds are infrequent in the clusters. The bond length of B-B is about 0.153-0.182nm and that of Mg-B is 0.221-0.231 nm. The outcome of population analysis suggests that there is an electronegative center in the cluster, the other B and Mg atoms with positive charge are located at apexes of the cluster.