Let us emphasise, that in this section we aim to estimate how well MACE approximates the DFT potential energy surface. Therefore, considering strictly equivalent minima allows us to understand how the single-point MACE errors along DFT PES translate to errors in the derived property, the BDE. This comparison also allows us to quantify the size of the effect that the miss-match of the local PES minima has on the overall error. Comparing the strictly matching PES minima is a simplification to comparing the free energies of bond dissociation. Free energy is the most appropriate metric to compare different methods and is preferable to both, matching the local minima (M vs D' or M' vs D comparison) and starting the procedure from an arbitrary starting geometry (D vs M). In computing the free energies, the contributions of different local minima are weighted appropriately, although that significantly increases the computational cost. Ideally, free energies would also be used in applications such as site of metabolism prediction illustrated in Figure . However, the effect of different conformations on the reaction energies has been found to be small for this application and thus only a single geometry is considered for computational efficiency . Ultimately, BDE error of 1.37 kcal/mol is close to the chemical accuracy of 1 kcal/mol that is required for models to be practically useful in realistic applications. As seen from learning curves in Figure