Cluster model DFT study of acetylene adsorption on the Cu (100) surface

The density functional theory and the cluster model approach have been used to study the adsorption of the acetylene molecule on the (100) surface of copper. Five possible adsorption sites have been considered: parallel twofold bridge, perpendicular twofold bridge, threefold hollow, diagonal fourfold hollow and aligned fourfold hollow sites. For each case, optimized geometries have been calculated. Vibrational frequencies have been calculated for the two energetically most favored adsorption sites. The results show clearly that on the (100) surface of copper the acetylene molecule adsorbs preferably on a fourfold hollow site. These theoretical results are in good agreement with recent Scanning Tunneling Microscopy results. (C) 2003 Elsevier B.V. All rights reserved.