X-ray form factors and the electronic structure of graphite

The bonding and spectroscopic properties of graphite are investigated by carrying out first-principles, self-consistent electronic structure calculations, and by comparing the results with high-resolution data from recent x-ray diffraction and angle-resolved photoemission measurements. The theoretical valence-charge density is in excellent agreement with values derived from experimental x-ray from factors. Unlike other group-IV covalent materials, the bonding charge exhibits a prominent double-humped structure due to the lack of p core states. The energy band structure is also in good agreement with experimental measurements and previous calculations.