Abstract: Ab initio molecular orbital method is used to theoretically investigate the interaction of water with the bridge site of graphite surface (0001). The adsorption energies in different directions are calculated at 6-31G^*, basis set level using C₆H₈ cluster. The results indicate that the interaction between water and graphite is weak and they belong to the physicosorption system. On the surface with no charge or with negative charges, when the atom Hof the water is near the surface, there is a minimum point on the potential energy surface; while on the surface with the positive charges, when the atom Ois near the surface, there exists a stable adsorption point. Whether the surface carries negative charges or positive charges, the interaction between the water and the graphite surface is strengthened.

Key words: Ab initio method, Graphite surface (0001), Water, Adsorption