Furthermore, we observe that relative energies of the studied systems are highly dependent on the functional used. GGA functionals are known to provide incorrect mechanistic insights if blindly applied to transition metal catalysts, and we show that this is even true for very simple main-group reactions like the cleavage of the N-O bond in N2O. Hybrid functionals overcome these problems to a large extent. We therefore advise the community to take special care when choosing functionals, even for very small and simple molecules as N2O. A minimum requirement should be the application of +U corrections (with careful choice of the U values used) or more recent developments in the field of approximate DFT methods like MO-DFT+U. The accuracy and transferability of the used functionals and methods should always be investigated for each reaction and compared to database values for similar small systems to prevent misguided conclusions.