Mechanism of CO chemisorption on a metal surface is discussed on the basis of self-consistent local-density-functional calculations using norm-conserving pseudopotential in the linear-combination-of-atomic-orbitals method. The CO/Pt(111) system is studied by the cluster model for metal surfaces by introducing a model potential intended to pick up surface states by placing dangling bonds around the cluster surface. The CO-2π state is found to lie about 2–4 eV above the Fermi level with weak bonding surface Pt atoms. The donation–back-donation mechanism is found to be unlikely in CO/Pt(111).

• Received 28 December 1993

DOI:https://doi.org/10.1103/PhysRevB.49.14619