Incoherent inelastic neutron scattering from liquid water: A theoretical investigation

A theory of incoherent inelastic neutron scattering from liquid water is presented, and recent experimental data obtained by employing the spallation sources are interpreted. This theory is a statistical theory, similar to those describing optical spectra of liquids. The experimental spectra of liquid ${\mathrm{H}}_2$O and ${\mathrm{D}}_2$O are reproduced theoretically. The incoherent neutron- and light-scattering spectra of water are compared. The suitability of this type of experiment to study high-frequency modes of translational-rotational motion of molecules in liquids is emphasized.