The remaining host-guest contribution is about 20 to 30 kJ mol -1 smaller than the TCS adsorption energies, indicating a preference for TCS over H2O. On a per molecule basis, the H2O adsorption energies correspond to -48.7/-53.3 kJ mol -1 for all-silica FAU/MOR. As guestguest interactions are virtually identical, the more negative value for MOR can be attributed to stronger interactions with the framework in the narrower channels. It has to be noted that these values are not directly comparable to thermodynamically measurable quantities that represent the intermolecular interactions in liquid water, specifically the enthalpy of vaporization (44 kJ mol -1 at 298 K). For a semi-quantitative estimation, however, they can be compared to the intermolecular contribution to the total energy obtained in DFT optimizations of a box of water molecules using the same approach. Calculations for four different boxes containing 256 H2O molecules (DFT-optimized density ≈ 1.06 g cm -3 ) delivered energies on the order of -60 kJ mol -1 per H2O molecule. In other words, the DFT calculations correctly predict the interaction to be weaker in the all-silica zeolites than in liquid water, in line with the This finding agrees with experimental observations and previous DFT results. The framework deprotonation precludes a simple calculation of the contribution of H2O-H2O interactions as done for the all-silica zeolites. However, it is apparent from Figure that the increase in interaction strength when moving from an all-silica zeolite to its protonated counterpart is much more pronounced for water than for TCS. The occurrence of framework deprotonation upon water adsorption, and its absence during TCS adsorption, also confirm the notion of a stronger interaction with water.