Calculations of Einstein A coefficients for transitions between vibrational levels in NO(a 4Π)

The dipole moment function calculated by Langhoff et al. [J. Mol. Spectrosc. 138, 123 (1989)] for NO(a 4Π) has been used in conjunction with an RKR potential to obtain the vibrational transition probabilities of this state, for levels v=1–19. The probabilities increase with v, from 5 s−1 for v=1 to a maximum of 34 s−1 for v=13. Spectral intensities have been calculated for the situation that a 4Π molecules are created at the top of the potential, and cascade down without collisional quenching. Inclusion of a radiative loss in the a–X system results in the accentuation of overtone 1100–2000 cm−1 emission in the spectrum. These infrared bands may be significant in an N+O recombination environment, such as afterglows and airglow.