We have performed first-principles calculations for the mechanic and electric properties of pure Pt nano-contacts and a Pt contact with a single CO molecule adsorbed. For the pure Pt contacts we see a clear difference between point contacts and short chains in good agreement with experiments. We identify a tilted bridge configuration for the Pt-CO-Pt contact, which is stable and has a conductance close to 0.5G0 (G0=2e2/h), and we propose that this structure is responsible for an observed peak at 0.5G0 in the conductance histogram for Pt exposed to a CO gas. We explain the main features of the transmission function for the Pt-CO-Pt contact, and show that the conductance is largely determined by the local d-band at the Pt apex atoms.
@article{arxiv.cond-mat/0512138,
title = {Electron transport in a Pt-CO-Pt nanocontact: First-principles calculations},
author = {M. Strange and K. S. Thygesen and K. W. Jacobsen},
journal= {arXiv preprint arXiv:cond-mat/0512138},
year = {2009}
}