Comparison between the observed abundance of H₂S in IC 348 (black dots) and chemical models. The top left panel shows the observed abundances compared to models with different initial sulfur abundances and the binding energies of Model 1 from Table 8. The sets of models that best fit the observations are shown with solid lines. The top right panel shows a similar comparison, but with the binding energies of Model 16 from Table 8, evidencing again the low impact of declining binding energies in the predicted gas-phase abundances of H₂S. The dependence between the sulfur abundance and the extinction is shown in the bottom left panel. The filled area S_H2S represents the appropriate ranges of sulfur abundances that models with other sets of binding energies apart from Model 1 (Table 8) require.