Gradual changes in electronic properties from graphene to graphite: first-principles calculations.

Calculations based on the first-principles pseudopotential plane-wave method and density functional theory are performed to investigate the electronic properties of graphene, bilayer graphene, multilayer graphene, and graphite. From an analysis of the electronic band structure close to the Fermi level, we have quantified the gradual change in the Fermi surface topology from the point-like structure for graphene to a warped triangular shape for graphite. We have also discussed the gradual change in the electron and hole effective masses and velocities as the system evolves from graphene to graphite.