  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.
