Abstract
Controlled doping of active carbon materials (viz., graphenes, carbonnanotubes etc.) may lead to the enhancement of their desired properties. The leaststudied case of C/Be substitution offers an attractive possibility in this respect. Theinteractions of Be2 with Be or C atoms are dominated by the large repulsive Pauliexchange contributions, which in turn offsets the attractive interactions leading torelatively small binding energies. The Be2 dimer, e.g., after being doped inside a planarcarbon network, undergoes orbital adjustments due to charge transfer and unusualintermolecular interactions and is oriented perpendicular to the plane of the carbonnetwork with the Be−Be bond center located inside the plane. The present theoreticalinvestigation on the nature of bonding in C/Be2 exchange complexes, using state of theart quantum chemical techniques, reveals a sp2 carbon-like bonding scheme in Be2 arising due to the molecular hybridization of σand two π orbitals. The perturbations imposed by doped Be2 dimers exhibit a local character of the structural and electronicproperties of the complexes, and the separation by two carbon atoms between beryllium active centers is sufficient to considerthese centers as independent sites.