Theoretical study of small MgO clusters

Abstract

We report a self consistent tight binding calculation of the cohesion energy of small MgO clusters, up to 12 atoms. We discuss the size variation of the charges, the bond lengths, the electronic gaps. For the first time, we predict the existence of a strong dimerization of the bond length in the small clusters. We underline the consequences of the competition between covalent and electrostatic effects in these ionocovalent systems.