Where E spec is the binding energy of the specific species, and E A is the binding energy of the adatom (C, H or O). X and X m are the bond order and the total possible bond order for the adatom (X C =4, X H =1, X O =2) on Pt(111). The four physisorbed species were not scaled from Pt(111) to Rh(111) because traditional LSRs cannot be applied to those species.