The final GRID descriptor is formed by concatenating the histograms of the first 100 groups, enabling numerical comparison between structures with different average density. Selecting the first 100 groups does not strictly enforce the 10 Å limit initially chosen, instead giving a skewed distribution of maximum distances peaking around 7.5 Å (Fig. ). This is sufficient to capture the structural features presented here, but longer distances could be considered at the expense of computational complexity.