Collision-interrupted librational model for molecular reorientation in liquids

Abstract

We propose a model for molecular reorientation in liquids where the molecules have been assumed to perform libratory motion in harmonic oscillator potentials with a continuous distribution of Ubrational frequencies. The molecular rotation is interrupted by instantaneous random collision. The exact correlation functions have been calculated using a Monte Carlo technique. The calculated correlation functions exhibit the features observed in experiments. The agreement with experiment is excellent as far as the orientational correlation functions are concerned, but is not so encouraging when simultaneous agreement with angular velocity and orientational correlation functions is considered. The shortcomings of similar models proposed earlier have been discussed.