In this case, since both CVs are maintained at the same pressure, gas molecules enter the system from both sides of the membrane. As the simulation progresses, sharp peaks in gas density appear, indicating that gas molecules are occupying the membrane's pores (panel (f)). By the time the system reaches equilibrium, as seen in Fig. (h), several peaks are observed with a major trough at the center of the membrane. Comparing panels (g) and (h), the positions and heights of the peaks are very similar, with the differences mainly attributed to the longer averaging time of 400 ns in panel (h) compared to 100 ns in panel (g). Based on this result,it is reasonable to conclude that the E-DCVMD system reaches equilibrium after approximately 100 ns, and therefore, only data from trajectories after the first 100 ns are used for further analysis.