Vibrational phase relaxation in ethane at moderate densities, including the critical region

Publisher Website
Google Scholar
Abstract
The bandwidth of the isotropic component and the frequency of the ν3 (C–C stretch) Raman band of ethane have been measured for a range of densities at constants temperature, and for a range of temperatures at the critical density. No critical anomaly is observed. The rotation-vibration coupling contribution to the bandwidth is calculated. The remaining contribution to the bandwidth increases with increasing density in a manner consistent with current theories that take into account both the repulsive and attractive intermolecular forces. However, the attractive force contribution cannot be related in a simple fashion to the macroscopic compressibility. Data taken over a wider range of density and temperature will be required to quantitatively determine the separate repulsive and attractive contributions to the width.