Another interesting conjecture may also be made. It is a wellknown fact that point defects tend to be subject to attraction force towards other defects (perturbations in the elastic field) and are also attracted to dislocations with elastic tensor and the electrostatic interactions being a driving force of this phenomenon. Since both -ad-atoms and dislocations generate FOs that may be responsible for the surface-mediated interactions, one might argue that FOs also play an important role and may even result in the formation of chains or islands of adsorbed entities. On the other hand, it is possible that the absence of extensive observations of ad-atoms located at a distance of the first energy minimum is due to interference of their FOs, resulting in stronger interaction with dislocations and edges and subsequent concentration there, forming bigger substructures (Fig. ). Another possibility is that atoms located at the first energy minimum of each other might be able to overcome a potential energy barrier, forming a pair. Subsequently, this may lead to the formation of bigger structures.