GRAPHITE INTERPLANAR BONDING - ELECTRONIC DELOCALIZATION AND VAN-DER-WAALS INTERACTION

The weak interplanar bonding in graphite is studied in the DFT formali sm. The decomposition of the cohesive energy in its kinetic, electrost atic and exchange-correlation parts, coupled with the analysis of char ge transfer, reveal an interplay between electronic delocalization and van der Waals contributions to the bonding. Without the latter, the i nterplanar cohesive energy would be at least 8.4 meV/atom (instead of 20 meV/atom). The delocalization explains why AB-stacking is favoured with respect to the AA-stacking and should appear in the intermolecula r bonding of solid C60 and in nanotubes bundles.