First-Principles Study on Structural Stability of Alkali and Alkali-Earth Coadsorbed on Cu(001) Surface

摘要

A coadsorbed system of Li and Mg on a Cu(001) surface is studied by means of first-principles total-energy calculations within the local density approximation. It is proved that a hybrid phase in which Mg atoms are located at substitutional sites by kicking out Cu row along the [010] direction and Li atoms occupy hollow sites is the most stable geometry in the coadsorption system. Mechanism of structural stability of this coadsorption surface is discussed by comparing optimized structure, adsorption energies and electron density distribution between related coadsorbed and adsorbed surface systems.