We also compute the potential energy surface (PES) of non-covalent complexes to search for possible states where chemisorption occurs (Fig. ). PES begins at intermolecular distances of dinter2. fullerenes reach highly stable chemisorbed states at room temperature due to the relatively high dissociation barrier to reach the physisorbed states (E  >0.7 eV) . The absence of an energy barrier to reach chemisorbed states is a consequence of phosphorene nonplanarity due to its shape of structural ridges; in contrast, the chemical Graphene-C60 attachment requires a high energy barrier due to the lack of local puckering in the graphene structure .