The DAC-SIM package is a python package integrated with the developed MLFF through the ASE calculator interface, for molecular simulations including Widom insertion, molecular dynamics, and geometry optimization. The Widom insertion simulations were conducted on the CoRE MOF 2019 dataset to determine Henry's law coefficient (KH) and heat of adsorption (Qst). Before performing the simulation, geometry optimization was implemented for each MOF structure. The optimization process includes a total of 30 steps, each consisting of 50 iterations of cell relaxation followed by 50 iterations of internal relaxation with the cell held fixed. The convergence criterion for the maximum force was set at 0.05 eV/Å to balance computational efficiency.