Nonrelaxational inertial motion in CS₂ liquid observed by femtosecond time-resolved impulsive stimulated scattering

Femtosecond time-resolved impulsive stimulated scattering data from CS₂ liquid are shown which clearly indicate an inertial component of the short-time motion which cannot be described in terms of Debye relaxational dynamics. This is interpreted in terms of the vibrational character of intermolecular motion in the liquid. A discussion of time-domain and frequency-domain light-scattering techniques is given to illustrate the comparative difficulty of characterizing this type of motion by conventional methods.