The most important descriptor is the exchange free energy "G_0" associated with lowpressure selectivity. Its contribution displays a very strong positive linear correlation (Figure ). This descriptor establishes a baseline, on top of which other contributions either decrease the free energy (more selective) or increase it (less selective). The model can be interpreted as a combination of a baseline and smaller adjustments estimating the deviation magnitude from the ideal low dilution case. For instance, the next two descriptors "G_900K" (900 K low-pressure exchange free energy) and "G_Xe_900K" (900 K low-pressure xenon adsorption free energy), further contribute to the baseline by providing information on lowpressure selectivity. Moreover, they also offer insights into the deviations necessary to differentiate structures experiencing a drop in selectivity from those maintaining their selectivity.