• vdW-DF2 gives rather similar results as PBE-D3, with 𝑚 12 amounting to 1.02 and a squared correlation coefficient of 0.96. rev-vdW-DF2 is the only functional for which the slope 𝑚 12 for XC1 = PBE-D3 is smaller than one, with the adsorption energies being about 8% less negative. Apart from a very strong correlation with vdW-DF2, correlations with other functionals fall in a range of 0.93 < 𝑅 2 < 0.97.