Adsorption of CN on Cu(100) surface studied by density functional theory

Using density functional theory (DFT), the adsorption of cyanide (CN) on the different sites of Cu( 100) surface was studied with end-on and side-on geometries. Cu-14 cluster was used to simulate the surface. The present calculations show that it is more favorable than other adsorption sites for the CN to bond to the top site via carbon with the molecular axis perpendicular to the surface. The calculated C-N stretching frequencies are red-shifted, expect CN adsorbed on the top site via carbon. For CN bonded to the surface via the carbon, the results of the density of states (DOS) and the charge analysis show that there are a strong a bonding and a weak pi anti-bonding between Cu and CN molecules.