Probing structural changes upon carbon monoxide coordination to single metal adatoms.

In this work, the adsorption height of Ag adatoms on the Fe₃O₄(001) surface after exposure to CO was determined using normal incidence x-ray standing waves. The Ag adatoms bound to CO ( Ag 1 CO ) are found to be pulled out of the surface to an adsorption height of 1.15 Å ± 0.08 Å, compared to the previously measured height of 0.96 Å ± 0.03 Å for bare Ag adatoms and clusters. Utilizing DFT+vdW+U calculations with the substrate unit cell dimension fixed to the experimental value, the predicted adsorption height for Ag 1 CO was 1.16 Å, in remarkably good agreement with the experimental results. [ABSTRACT FROM AUTHOR]