In the current study, to estimate the energy barriers that prevent gas release, we performed, on the one hand, nudged elastic band (NEB) computations at the moderate cost of GGA density functional theory and, on the other hand, assessed accuracy of the so-obtained NEB trajectories through further single-point computations at the higher accuracy and cost of hybrid, meta-GGA and double hybrid density functionals. An overview on the so-obtained activation energies is summarized in Table ; corresponding potential energy profiles are visualized in Figure .