Thermal behavior of hydrogen atom intercalated between two layers of C150H30 graphite plane: MD simulation Original Research Article

For investigation of thermal behaviors of hydrogen (H) atom in a graphite intercalated compound (GIC), the molecular dynamic (MD) procedure at the molecular mechanics 2 (MM2) level was applied to a hydrogen terminated cluster model composed of two layers of C150H30 plane. On the basis of the optimized structure, one intercalated H atom was stabilized at the mass center of the cluster model. According to the trajectory of the intercalated H atom, the diffusion is initiated at 100 K towards lower potential energy area in the periphery of the cluster model. The diffusion rate increased with the increase in the simulation temperature from 100 to 500 K. According to the extended Hückel calculation, the band gap of graphite is broadened by 0.1 eV with the intercalation. Thus, the present MD simulation proposed that the semiconductivity of GIC is promoted due to the development of the ionic conductivity. However, H atom adsorbed on the surface of C150H30 plane formed the stable covalent bond with a host carbon atom and made little contribution to the conductivity.