Firstly, in the case of GUJVOX, while the CO2 Qst remained above 50 kJ/mol, the H2O Qst exhibits a substantial increase in the UFF+DDEC calculation. The presence of the electronegative functional group (SO4 2-) within the framework, which acts as a strong binding site for H2O, appears to be a major factor in this discrepancy. The point charges for S in SO4 2-are +1.5, while for O in SO4 2-, they are -0.7, indicating significant polarization within this moiety (see Figure ). As discussed with Figure (b), UFF+DDEC encounters challenges in accurately simulating highly polarized moieties, leading to a general overestimation of interactions with H2O compared to CO2.