Lifetimes and predissociation mechanisms of O+2 b 4Σg−(v = 5–8)

Abstract

Predissociation linewidths (lifetimes) of the O⁺₂ b ⁴Σ⁻_g state have been measured as a function of both rotational levels N and spin‐orbit fine structure components F₁, F₂, F₃, and F₄ for vibrational levels 5 through 8. The lifetime variation is inconsistent with predissociation by either the d ⁴Σ⁺_g state or the f ⁴Π_g state alone, but can be explained by assuming both states participate in the dissociation. Analysis of the linewidth variation, using an experimentally determined f ⁴Π_g potential curve, allows a separation of the effects of the ⁴Σ⁺_g and ⁴Π_g states on the predissociation. The experimental linewidths are compared with theoretical calculations and found to be about a factor of 3 larger than calculated. Relative transition moments from the a state to the d and f states are estimated using a single configuration interaction calculation.