Performing geometric relaxations of our model system, as described above for the selected set of PDs we identify common themes across the final configurations. These are characterized by a combination of the N 2 bond length and orientation on the Li100 surface. Using SOAP, we encode all relaxed N 2 configurations on Li100 in the presence of each PD. As stated in the methods section, we removed the PD from the calculated slab encodings to focus on the N 2 configurations on Li. Additionally, to ensure consistency in analyzing the structures, any final configurations that explicitly resulted in proton transfer to the nitrogen were excluded, as this change in PD makes its removal from the surface ambiguous. Projecting these geometrical representations onto two dimensions, Uniform Manifold Approximation and Projection (UMAP) is applied and visualized in Fig. .