ANALYTICAL EVALUATION OF THE MAXWELL-BOLTZMAN VELOCITY AVERAGE IN PRESSURE-BROADENED HALFWIDTH CALCULATIONS: APPLICATION TO OZONE
Loading...
Date
2001
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
Ohio State University
Abstract
For the first time the halfwidth within the Complex Robert-Bonamy (CRB) formalism is calculated without making the mean-relative thermal velocity approximation. The application is to nitrogen-broadened halfwidth of the 500.4 GHz transition ($34 _{232}$ <- $34 _{133}$) of the ground vibrational state of ozone. For each states of the perturber, the optical cross-sections are determined at a number of velocities with the intermolecular potential taken as a sum of electrostatic contributions and Lennard-Jones (6-12) atom-atom components. The dynamics of the collision process are correct to second order in time. Using a non-linear least-squares fitting method, the optical cross-sections are fit to a double power law, which allows the velocity integral for the halfwidth to be done analytically. The results are compared with the mean-relative thermal velocity Complex Robert-Bonamy calculations and with measurement. The temperature dependence of the halfwidth, which is necessary for reduction of remotely sensed data, is determined from both methods and compared with experiment.
Description
Author Institution: Department of Chemistry, University of Massachusetts Lowell