Electron-hole and plasmon excitations in 3d transition metals: Ab initio   calculations and inelastic x-ray scattering measurements
  We report extensive all-electron time-dependent density-functional calculations and nonresonant inelastic x-ray scattering measurements of the dynamical structure factor of 3d transition metals. For small wave vectors, a plasmon peak is observed which is well described by our calculations. At large wave vectors, both theory and experiment exhibit characteristic low-energy electron-hole excitations of d character which correlate with the presence of d bands below and above the Fermi level. Our calculations, which have been carried out in the random-phase and adiabatic local-density approximations, are found to be in remarkable agreement with the measured dynamical structure factor of Sc and Cr at energies below the semicore onset energy (M-edge) of these materials. 
I.G.Gurtubay, J.M.Pitarke, Wei Ku, A.G.Eguiluz, B.C.Larson,   J.Tischler, P.Zschack, and K. D. Finkelstein