Probing high-energy electronic excitations using inelastic neutron   scattering
  High-energy, local multiplet excitations of the d-electrons are revealed in our inelastic neutron scattering measurements on the prototype magnetic insulator NiO. These become allowed by the presence of both non-zero crystal field and spin-orbit coupling. The observed excitations are consistent with optical, x-ray, and EELS measurements of d-d excitations. This experiment serves as a proof of principle that high-energy neutron spectroscopy is a reliable and useful technique for probing electronic excitations in systems with significant crystal field and spin-orbit interactions. 
Young-June Kim, A. P. Sorini, C. Stock, T. G. Perring, J. van den   Brink, and T. P. Devereaux
cond-mat.str-el