Abstract
We show that a simple first-principles correction based on the difference between the singlet-triplet CO excitation energy values obtained by density-functional theory (DFT) and high-level quantum chemistry methods yields accurate CO adsorption properties on a variety of metal surfaces. We demonstrate a linear relationship between the CO adsorption energy and the CO singlet-triplet splitting, similar to the linear dependence of CO adsorption energy on the energy of the CO orbital found recently [Kresse et al., Phys. Rev. B 68, 073401 (2003)]. Converged DFT calculations underestimate the CO singlet-triplet excitation energy whereas coupled-cluster and configuration-interaction (CI) calculations reproduce the experimental The dependence of on is used to extrapolate for the top, bridge, and hollow sites for the (100) and (111) surfaces of Pt, Rh, Pd, and Cu to the values that correspond to the coupled cluster and CI value. The correction reproduces experimental adsorption site preference for all cases and obtains in excellent agreement with experimental results.
- Received 29 October 2003
DOI:https://doi.org/10.1103/PhysRevB.69.161401
©2004 American Physical Society