THE EFFECTS OF CENTRIFUGAL-DISTORTION ON THE INFRARED RADIATIVE TRANSITION-PROBABILITIES OF NO(X(2)PI)

State-to-state and thermally averaged Einstein A-coefficients have bee n computed for the fundamental and first three overtone sequences of t he NO (X(2)II-X(2)II) system with the aim of examining the effects of centrifugal distortion on the high-J transitions that occur as a resul t of upper atmospheric chemistry. The Einstein coefficients were calcu lated using an experimentally derived dipole moment function of Rawlin s et al (manuscipt in preparation), and the ab initio dipole moment fu nctions of Langhoff et al [Chem. Phys. Lett. 223, 416 (1994)] and de V ivie and Peyerimhoff [J. Chem. Phys. 89, 3027 (1988)], for J' ranging up to 139.5. The state-specific Einstein coefficients show that, regar dless of dipole moment function employed, centrifugal distortion has a relatively small effect on the Delta v = 1 sequence which is manifest primarily as a reduction in the high-J R-branch intensities. However, the effect on the overtone rotational intensities is larger and resul ts in enhanced R-branch intensities and reduced P-branch intensities r elative to those calculated neglecting centrifugal distortion. For exa mple, in the first overtone system for J' approximate to 80.5, v' = 2- 14, the ratio of R- to P-branch Einstein coefficients is larger by abo ut 1.7 than the R/P ratio predicted in the absence of centrifugal dist ortion.