2D potential cuts through the 6D PES for dissociative adsorp- tion of H2 on Pt(211) along r and Z at the nine different sites on the (1 × 1) unit cell. In all cases H2 approaches parallel to the macroscopic surface (θ = 90◦). Top views of the molecular configurations are shown as insets. Contour levels are give in the energy range of [-1, 2] eV with a spacing of 0.2 eV. The zero-value of the PES is set equal to the gas phase minimum energy. Negative (positive) valued contour lines are plotted in blue (black) and the zero-valued contour line is shown in red. Green circles indicate the position of the reaction barrier, and barrier heights E† are also shown.