Molecular dynamics in liquids from femtosecond time-resolved impulsive stimulated scattering

Molecular motions in simple liquids are observed on the femtosecond time scale by means of impulsive simulated scattering. In carbon disulphide and benzene liquids, weakly oscillatory time-dependent responses are observed. These are interpreted in terms of molecular orientational motion which at short times is vibrational (i.e. librational) in character due to intermolecular interactions. In CS/sub 2/, the dephasing of the oscillations is primarily inhomogeneous. Temperature-dependent values of the configuration-averaged librational frequency and the extent of its inhomogeneity are determined.>