Unique geometric and electronic structure of CO adsorbed on Ge(100): A DFT study

► DFT calculation found CO is exclusively adsorbed on lower Ge dimer atom on Ge(100). ► The bonding between Ge and CO is mainly attributable to the Ge 4pz orbital overlapping with C 2s. ► The adsorption and diffusion processes were studied. ► The adsorbate interaction is negligible.