Comparative study of the valence electronic excitations of N2 by inelastic x-ray and electron scattering.

Bound-state, valence electronic excitation spectra of N2 are probed by nonresonant inelastic x-ray and electron scattering. Within usual theoretical treatments, dynamical structure factors derived from the two probes should be identical. However, we find strong disagreements outside the dipole scattering limit, even at high probe energies. This suggests an unexpectedly important contribution from intramolecular multiple scattering of the probe electron from core electrons or the nucleus. These effects should grow progressively stronger as the atomic number of the target species increases.