These optimal values align with the physical requirement of having xenon-sized pores to enhance xenon's attraction, as identified in various literature papers. However, it should be noted that these values are slightly higher than those mentioned in the literature due to differences in atom radius definitions. Moreover, values of "delta_G0_298_900" between 4 and 6 kJ mol -1 (Figure ) have a higher likelihood of contributing negatively, indicating lower ambient-pressure selectivity. These sweet spots provide valuable insights for distinguishing truly selective materials from others. Some SHAP dependence plots have a rather linear domain for the most selective structures (in blue) -a good linear contribution is observed for the difference of pore volumes between Xe and Kr sized probes "delta_VF_18_20" (Figure ). This implies that a lower void fraction difference corresponds to a more selective structure. The same trend is observed for the standard deviations of the PSD, denoted as "pore_dist_std", and the Boltzmann weighted krypton interaction energies distribution, referred to as "enthalpy_std_krypton". Optimal values for these descriptors tend to be zero. As the value approaches zero, the contribution becomes more negative, indicating a more selective structure at ambient pressure.