Several attempts to stabilize the HB structure on surface have been made, although, in all cases, the herringbone configuration was lost in a few ps, probably also because the initial packing is not optimal since is extracted from the bulk crystal structure by removing the interactions with CPPs in other crystallographic directions. For this reason, in order to optimize the packing of an adlayer composed by molecules in the vertical configuration, and starting from the HB structure mentioned before, we applied an external pressure of 1 atm to the system in the plane direction. To avoid the molecules to go out of the plane, their positions were restricted to move in the directions inside the plane by adding a harmonic potential to the out-of-plane displacement. This strategy was successful and finally a (meta)stable crystalline structure was obtained. The main difference between the experimental crystalline HB arrangement in the bulk and the new structure found is that the HB interactions, labelled as v 2 in Table , involve pairs of molecules with non-orthogonal ring planes and stacked in a convex-concave (CC) disposition (see Fig. ). A similar configuration has been very recently reported by Spisak et. al. for [6]CPP crystals growth by sublimation and deposition. The area of the new structure is a 21% less than the area of the original HB structure. This configuration is not observed in the simulation of the tridimensional crystal, that preserves the HB structure shown in ), is found to be -63.0 kcal/mol per molecule, corresponding to an energy per area unit of -98.2 kcal/nm 2 , hence much larger than the one obtained for the orthogonal HB disposition. The in-plane radial distribution function in Figs. and shows that both the hexagonal and the second concave-convex structure preserve their crystalline order on graphite, and allows for a direct measurement of the lattice parameters (a = 14.2 Å for hexagonal, and a = 12.86 Å and b = 9.88 Å for the concave-convex configuration).