An inconsistency was pointed out in the adsorption energy values, for O diffusion on Pt (111) surfaces, which had been reported in recent studies. In one of them, there was a scanning tunnelling microscopy-deduced value of 0.43eV for the diffusion barrier. In a second study, the calculated adsorption energy difference between face-centered cubic and hexagonal close-packed had been given and, in the third study, the scanning tunnelling microscopy-identified metastability of O in hexagonal close-packed sites had been given. By using accurate first-principles density-functional methods, full agreement was obtained here between the second 2 studies; plus a diffusion barrier of 0.58eV which was consistent with a reinterpretation of the raw data in the first study.

A.Bogicevic, J.Strömqvist, B.I.Lundqvist: Physical Review B, 1998, 57[8], R4289-92