Theoretical study of interactions between the Si(1 1 1) surface and metal atoms

We investigated the interactions between the Si(1 1 1) surface and the Na and Mg atoms using cluster model calculations. Calculations were performed at levels of the complete-active-space self-consistent-field and multi-reference single and double excited configuration interaction calculations using the model core potential method. Our calculations revealed that the most favorable sites of Na and Mg adsorption on Si(1 1 1) are on-top (T1) and bridge (B2) sites, respectively. The nature of chemical bonds between these metal atoms and the dangling bonds of the surface Si atoms are found to be essentially covalent.