Charge decomposition analysis of the chemisorption bond

Charge decomposition analysis (CDA) has been applied to study the interacti on of CO and NH3 on several metal surfaces. For NH3 chemisorption, CDA pred icts a large donation from the NH3 lone pair to the surface and a vanishing contribution for the backdonation. However, for CO chemisorption, CDA pred icts the a-donation to be larger than the pi-backdonation, contrary to othe r methods. CDA overestimates the extent of the sigma-donation because of it s large overlap with the metal orbitals compared with the overlap of the pi orbitals. The same situation is found in Ni(CO)(4). Therefore, the CDA met hod should only be applied to the investigation trends. (C) 2000 Elsevier S cience B.V. All rights reserved.