This study aims at building an ML model to predict the Xe/Kr ambient-pressure selectivity faster than standard techniques. To obtain reference values (ground truth in this study), we use the RASPA2 software to run GCMC calculations of 20:80 Xe/Kr mixtures at 298 K and 1 atm on our cleaned database. The van der Waals interactions are described by a Lennard-Jones (LJ) potential with a cutoff distance of 12 Å. The LJ parameters of the framework atoms are given by the universal forcefield (UFF), and the guest atoms (xenon and krypton) have their LJ parameters taken from a previous screening study. The study only focuses on a given Xe/Kr composition usually obtained by cryogenic distillation of ambient air 1 as a first step towards predicting other mixtures at different physical conditions (e.g. Xe/Kr mixtures out of nuclear off-gases).