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Title

Improved Line-Broadening Coefficients for Asymmetric Rotor Molecules with Application to Ozone Lines Broadened by Nitrogen
Authors

S. Neshyba
R. Gamache
Journal / Anthology

Journal of Quantum Spectroscopy and Radiation Transfer
Year: 1993
Volume: 50
Issue: 5
Page range: 443-453
Description

A procedure for obtaining atom-atom intermolecular potentials from the two-center expansion using symbolic manipulations in FORTRAN and Mathematica on a computer is described. The atom-atom potential for an XY2 molecule (C2v symmetry) and a linear, AB, molecule with the XY2 molecule positioned in the molecule-fixed axes in two different orientations (representations), labeled IIR and II L, are calculated. It has been found that the previous development of the atom-atom potential in the IIR representation is incorrect and leads to a mixed formulation with electrostatic terms in the IR and atom-atom terms in the IIIL representation. Broadening-coefficient calculations presented here show that when the correct potential is used anomalous oscillations in the Ka'=1 transitions for O3 broadened by N2 disappear. Further investigation has shown that the variations can be associated with particular quantum state symmetries. Improved agreement with the experimental measurements is observed.
Subjects

*Science > Physics > Nuclear and Particle Physics
*Science > Physics > Quantum Physics