• For alkanes, standard GGA functionals like the Perdew-Burke-Ernzerhof (PBE) functional in conjunction with pairwise dispersion corrections, like the D2 or D3 corrections developed by Grimme and co-workers or the TS correction proposed by Tkatchenko and Scheffler, have a systematic tendency to overestimate the interaction strength, i.e., they deliver "too negative" adsorption energies. While the tendency is generally observed, the degree of overestimation varies across studies. It also depends on the specific adsorbate studied.