Theory of orthogonal interactions of CO molecules on a one-dimensional substrate

A minimal model based on density-functional theory is proposed and solved to explain the unusual chemisorption properties of carbon-monooxide (CO) molecules on Cu(110)-(2 × 1)-O quasi-one-dimensional (1D) surface reported in Feng. The striking features of CO adsorption include (1) the strong lifting of the host Cu atom by 1 Å, and (2) the highly anisotropic CO-CO interaction leading to self-assembly into a nanograting structure. Our model implies that the 1D nature of the surface band is the key to these two features. We illustrate how formation of a chemical bond through specific orbital interactions between an adsorbate and 1D dispersive states of the substrate can impact the surface geometrical and electronic structure. © 2012 American Physical Society.We thank DOE-BES Division of Chemical Sciences, Geosciences, and Biosciences for support through Grant No. DE-FG02-09ER16056, W. M. Keck foundation, Ministerio de Ciencia e Innovación (Grant No. FIS2010-19609-C02-00) and G.V.-UPV/EHU (Grant No. IT-366-07) for financial support.Peer Reviewe