Effects of electron-hole interaction on the dynamic structure factor: Application to nonresonant inelastic x-ray scattering

We present a first-principles scheme for calculating the dynamic structure factor for conventional semiconductors and insulators. The dynamic structure factor relates closely to the inelastic x-ray scattering double-differential cross section for valence electrons, an application that we consider, but it is also probed using other techniques, such as electron energy-loss spectroscopy. In the present scheme the electron-hole interaction is taken into account. Theoretical results are compared with nonresonant inelastic x-ray scattering results for LiF, diamond, and wurtzite GaN. We show the importance of including the electron-hole interaction. Some other properties of an electron-hole pair in these materials are also studied.