Elbow plots (i.e., V (Z, r)) of the H2 + Ag(111) PES computed with the SRP48 functional and interpolated with the CRP method for four high symmetry configurations with the molecular axis parallel to the surface (θ = 90◦) as depicted by the insets, for (a) the top site and φ = 0◦, (b) the bridge site and φ = 90◦, (c) the fcc site and φ = 0◦, and (d) the t2f site and φ = 120◦ . Barrier geometries are indicated with white circles, and corresponding barrier heights and geometries are given in table 4.3 in the paper