Predissociation linewidths of the (3,0)-(11,0) Schumann-Runge absorption bands of 18O2 and 16O 18O in the wavelength region 180-196 nm

Predissociation linewidths of the (3,0)–(11,0) Schumman–Runge bands of 18O2 and 16O 18O in the wavelength region 180–196 nm have been obtained from the published measurements of the absolute absorption cross sections of Yoshino et al. [Planet. Space Sci. 36, 1201 (1988); 37, 419 (1989)] and spectroscopic constants of these molecules of Cheung et al. [J. Mol. Spectrosc. 131, 96 (1988); 134, 362 (1989)]. The linewidths are determined as parameters in the nonlinear least‐squares fitting of calculated to measured cross sections. Predissociation maxima are found at upper vibrational levels with v’=4, 7, and 10 for 18O2 and for 16O 18O. Our predissociation linewidths are mostly greater than previous experimental values for both isotopic molecules.