When comparing SOM III and IV, an interesting behavior emerges: SOM III induces a much higher trapping probability than SOM IV, although the diffusion of HCB is similar in both cases. This suggests that the low diffusion of HCB can be caused by different mechanisms, which would be either the direct trapping of the molecule (SOM III) or the slowdown of the molecules via the interactions with the HS molecules without trapping (SOM IV). The difference between HCB and water diffusion for the respective cases, which is higher for the SOM III case, should probably also be taken into account here. Furthermore, it is assumed that the high trapping probability for SOM III is connected to the strong interaction of HCB with the HS aromatic compounds, also indicated by a high occurrence of π -π stacking configurations and the correlation of these configurations to the trapping of the molecule (please refer to Section S9 (SI)). Overall, this analysis illustrates the complexity and variety of factors that influence the diffusion of the pollutant molecules in SOM.