Structures and vibrational frequencies of CO adsorbed on transition metals from calculations using the vdW-DF2 functional

•DFT calculations of CO adsorption on surfaces and clusters of 7 transition metals.•Site preferences and adsorption energies well reproduced with vdW-DF2.•Calculated vibrational frequencies systematically lower than experimental values.•After uniform scaling, mean absolute deviation ∼13cm−1 for all systems.•Vibrational spectra of dense layers of CO on Co(0001) and Pd(111) rationalized.