Adsorbate effects of CO molecules on the conductance of a free-standing gold monatomic chain

Equilibrium structure and electronic transport properties of a gold nanowire made of a three-atom chain suspended between two gold electrodes, and chemical modification of the wire via the adsorption of a carbon monoxide molecule, are investigated with density functional theory (DFT) calculations and the DFT-based Greenʹs function method. Contrast to previous reports, our study reveals that the adsorption of one CO molecule only modifies the atomic structure of the gold monatomic chain slightly and has little influence on the electronic transport properties near the Fermi level. Structural modification and interaction between electronic states resulted from the molecular adsorption are investigated in detail to improve our understanding of these calculation results.