Collision Broadening of Rotational Absorption Lines. II. Self-Broadening of Symmetric-Top Molecules

Abstract

A recently developed theory of the broadening of rotational absorption lines due to intermolecular collisions has been applied to available experimental data on CH3Cl, CH3F, CHF3, and PF3. It is shown that rotational energy transfer for these symmetric-top molecules is almost entirely dependent on dipole—dipole interactions, so their linewidths are calculable entirely from well-known molecular parameters resulting in a stringent test of the theory. The agreement, in general, is very satisfactory. Calculations are also presented based on earlier theoretical methods.