By Anthony Lim

The properties of a single graphene sheet have been of great interest to the scientific community. Many of its fascinating properties come from the band structure.Normally DFT calculations are used, however these are computational expensive. However, graphene is one of a few materials that can be well represented by a tight binding approach using one s orbital per atom.The beauty of such an approach is that it is analytic for a 1st nearest neighbour model. In tight binding there are 3 parameters;

  • γ0 is the hopping matrix element
  • s0 is the overlap of the orbitals on different atoms
  • epsilon is the onsite energy.

In the interactive graphic all 3 of these parameters are adjustable. By changing the parameters it is even possible to create a semi-conducting graphene sheet.