As to what is seen in the matrix of Figure , the matrix of Figure (right) shows that at 500 K the surface of Ih 309 NP is basically pre-melted (p ii of surface AEs < 0.5, meaning that in ∆t = 1 ns the atoms in those AEs have a higher probability to move to another AE, rather than to remain in the same one). This indicates that the entire Ih 309 has atomic dynamics faster than the nanosecond scale (liquid-like dynamics). On the other hand, at the resolution of our analyses, the atomic dynamics on the NP surface appear as more "discrete" at 300 K and 400 K (solid-like dynamics).