Calculation of the electronic and elastic properties of carbon

By accurately fitting tight-binding parameters to ab initio band structures from different tetrahedral volumes, tight-binding parameters have been developed for carbon. The model has scaling form similar to the tight-binding Hamiltonian of Xu et al. However, the properties of the higher-coordinated metallic structure are well described by the model in addition to those of the lower-coordinated covalent structures. This one reproduces accurately the band structures of carbon polytypes and gives a good description of the elastic constants for carbon in diamond structure. Results for phonon frequencies in crystalline carbon are also presented.