The Tight-Binding method: application to AB s-valent dimer
  The AB s-valent dimer is used to analyse bond formation and charge transfer within the tight-binding (TB) approximation. In this way a physical interpretation of the electronic structure and binding energy within density functional theory (DFT) is obtained which lends itself to the derivation of covalent and ionic interatomic potentials. 
D. G. Pettifor
cond-mat.mtrl-sci physics.chem-ph