Figure shows the PCA (projection on the two first components PC1 and PC2) of the SOAP power spectra dataset, colored based on the SOAP clusters detected via unsupervised HDBSCAN* clustering. From the inverse logarithm of the PCA density, it is also possible to obtain the pseudo-free energy surface of Figure . From these two plots, we can clearly distinguish three different zones on the PCA and obtain the first qualitative information on their interconnection. The clump of AEs on the left collects the bulk and sub-surface environments (dark blue, violet, and light blue). These SOAP environments correspond to quite dense areas in the PCA, which indicates substantially low mobility at 300 K of the atoms that belong to these AEs in the Ih 309 NP. The right part of the PCA is much less compact, indicating that the surface AEs (dark-, light-green, and yellow AEs: faces, edges, and vertexes) are in comparison much more dynamic at 300 K. Between the bulk and surface areas, there is a smaller zone in the PCA connecting them. The vast majority of these environments are classified as "Concave" (pink), which suggests that at room temperature the interior and exterior of these NPs communicate essentially via the creation of local "point defects" created on their surface -if we think of rosettes in this sense, as they are not present in the ideal icosahedral NP. Note that, being extracted from the densities of the states visited during the MD, the energy landscape of Figure is not a real free-energy surface. Nonetheless, this shows (i) how the various detected SOAP clusters (AEs) correspond to local density maxima and energy minima and (ii) that the barriers separating the surface states are relatively low, which allows for the considerable atomic exchange between these AEs.