The global minimum configuration was calculated by a constrained minima hopping method , as implemented in ASE. The method finds the global minimum structure using a combination of molecular dynamics (MD) and DFT geometry optimization . In the constrained minima hopping, adsorbed molecules were allowed to move and find another minimum with fictitious springs applied between adatom-surface atoms and among adsorbate atoms to prevent desorption or bond dissociation during the MD subroutine. Also, to speed up the calculations, surface atoms were fixed. The method parameters were: initial MD temperature (T 0 ) of 2000 K, initial acceptance energy threshold (E diff, 0 ) of 2.5 eV, and spring constant of 10 eV/ Å2 . The search for new minima was terminated when the MD temperature was raised above 4000 K. As a result, a collection of minima was found at each coverage, and the lowest energy configuration among the collection of minima was selected as a global minimum configuration. A final geometry optimization was performed on the lowest energy structures where the two top layers of the surface were relaxed. The adlayer configuration of CO * on Co(0001) was obtained by using the same minima hopping procedure.