Finally, to confirm the existence of permanent porosity in [RCC1-IM][NTf2]6 and the size-exclusion of the NTf2 counterions, MD simulations were performed at the experimental conditions for the liquid material (1 bar, 363 K). A simulation box was constructed featuring 48 cage molecules and 288 anions, retaining the required 1:6 cage:anion ratio (Fig. ). The starting lattice was equilibrated to a reasonable density of 1.342 ± 0.005 g cm -3 (Fig. , Table ), comparable to the experimental densities of analogous ionic liquid systems. The [RCC1-IM][NTf2]6 system was simulated for 10 ns. The liquid configuration was analysed by comparing the radial distribution function of [RCC1-IM][NTf2]6 with an analogous ionic liquid, [BMIM][NTf2] (Fig. ). We observe peaks in the same positions as those reported in the literature for the analogous ionic liquid; this suggests that the simulation is performing as expected. To examine the porosity exhibited by [RCC1-IM][NTf2]6, we compared the distribution of the cage cavity diameters over the full MD simulation and a simulation featuring only a single cage molecule in isolation (Fig. ). The cavity diameter distribution for the full liquid simulation was generated using Zeo++, and presents a histogram of the largest cavity diameter at each sampled timestep of the simulation. The distribution for the solo cage simulation is obtained from an MD simulation of a single cage molecule in gas; the histogram of the largest cavity diameter at each timestep is calculated using pyWindow. The distribution of cage cavity diameters over the course of the liquid simulation falls within the distribution for the cage cavity diameters from a simulation of a single cage molecule. This overlap further demonstrates that the observed void space in the full liquid simulation is not solely due to the transient void space inherent to the IL structure of the system, and is additionally supported by void space analyses of similar, neat imidazolium-based ILs. This supports the hypothesis that the observed experimental gas uptake is due to the porosity of the [RCC1-IM][NTf2]6 system. The narrower distribution of the cage cavity diameters from the full liquid simulation is caused by the pressure of the surrounding counterions, which impede the dynamics of the cage molecule compared to a single molecule in the gas phase.