where the E CP P (i)-Surf ace is the interaction energy of the CPP molecule with the The aggregation studies of monolayers in the VC was not explored in detail due to the relative instability (i.e. compare Figs. and) of a single molecule adsorbed in that configuration described above. Nonetheless, a possible monolayer structure with molecules in the VC was tested as a proof of concept. The proposed structure has been extracted from the experimental crystal, choosing the plane with the biggest stabilization energy (i.e the (1 0 1) plane, see Table ), forming a herringbone (HB) structure: a rectangular cluster of 48 molecules with initial dimensions 6.096×6.408 nm (which corresponds to a 3×8 replica of the herringbone unit cell) adsorbed on the graphite layer. The adsorption energy in the HB structure is now -55.4 kcal/mol, compared with the value of -73.1 kcal/mol found in the hexagonal structure, but the stabilization energy per unit area is instead larger for the HB packing, being -41.9 kcal/nm 2 for the hexagonal structure and -68.1 kcal/nm 2 for the herringbone one. The E CP P (i)-surf ace term is now -22.9 kcal/mol, which thus implies -32.5 kcal/mol of stabilization with its neighbors. We followed the evolution of this herringbone cluster during 10 ns at a temperature of 200 K and, as it was also expected, it proved to be unstable. At very short simulation times, some molecules at the borders of the cluster collapse in the HC. In addition, the crystalline packing, present in the initial configuration, is lost. In the next section we will further discuss the instability of this configuration.