The Widom insertion simulation results derived from our developed MLFF (MACE-DAC-1) using DAC-SIM were systematically compared with those obtained from a classical force field approach. In the classical method, the UFF 18 combined with density derived electrostatic and chemical (DDEC) charges (hereinafter referred to as UFF+DDEC) were used to simulate the CO2 and the H2O adsorption properties in the MOFs. UFF is interatomic potential consisting of empirical parameters and DDEC charges are derived from DFT calculations. A total of 2,654 MOFs, having the calculated DDEC charges provided by Kancharlapalli et al. were used for this analysis. Figures 4(a) and present the Qst distributions for CO₂ and H₂O, respectively, as computed using the DAC-SIM package with the developed MLFF and the RASPA software with the UFF+DDEC method. The overall distribution of CO2 Qst values from DAC-SIM closely resembles that obtained with UFF+DDEC; however, a notable difference is a minor peak at the lower range near 0 kJ/mol. As shown in Supplementary Figure , the LCD distribution of these MOFs exhibiting CO2 Qst values below 2.5 kJ/mol shifts to a lower range compared to the structures before undergoing geometry optimization. That is, the shrinkage in pore size occurred during the prior geometry optimization stage before Widom insertion simulation, thereby preventing them from accommodating CO₂ molecules. This highlights the advantage of DAC-SIM, enabling computationally efficient geometry optimization with accuracy near that of DFT prior to Widom insertion simulation, by improving force predictions in the finetuning stage.