A primary objective of this work is to assess whether well-established experimental trends, particularly the permeability perm-selectivity trade-off, commonly referred to as the Robeson boundary, can be replicated within a simulation framework. We investigate a selection of polymer membranes chosen based on their experimental gas separation performance. Atomistic models of these membranes are constructed, and performance metrics are calculated using the DCVMD method. When plotted on a Robeson plot, the simulated results reveal a distinct trade-off between permeability and perm-selectivity, qualitatively capturing the Robeson upper bound.