Inelastic X-ray scattering study on molecular liquids

Inelastic X-ray scattering (IXS) spectra of liquid water are re-examined. At low momentum transfer the dipole approximation is justified and the reflectance spectrum calculated from IXS data agrees fairly well with the optical one. At finite momentum transfer the data are presented in the form of the Bethe surface where the energy transferred is from 0 to 200 eV and the momentum transferred is from 0.19 to 3.59 a.u. Observed features are more diffuse than those of the theoretically anticipated models. (C) 2000 Elsevier Science Ltd. All rights reserved.