On extended diffusion models for asymmetric top molecules in liquids

Abstract

The extended rotational diffusion models are generalized to treat liquids composed of asymmetric top molecules. The correlation functions and their Fourier transforms are determined by both an analytical mechanics approach and a memory function approach. The limit of very short angular momentum correlation time is examined and is compared with the Debye anisotropic rotational diffusion model. The results are applied to infrared and Raman spectroscopy. A series of representative band profiles is presented. For asymmetric top molecules, the J-model is shown to be more realistic than the M-model.