Approximate spectral absorption coefficients of electronic transitions in diatomic molecules

Spectral absorption coefficients for electronic transitions in diatomic molecules have been calculated for a total of 50 transitions in 23 different molecules. The calculation is based on a “smeared” line model of individual vibrational bands and an anharmonic-oscillator semi-rigid rotator model for the vibrational-rotational energies. Improvements over similar calculations include the use of explicit band head positions and the effect of reversed bands. Comparison of the results of the smeared line model calculations based on (1) a perturbed harmonic oscillator potential for the NO-γ band system and (2) a Rydberg-Klein-Rees potential for the CN-Red band system have been made and show excellent agreement.