Complex resonances in the predissociation ofCs2

We present detailed quantum mechanical analysis of the complex resonances observed in molecular predissociation. The complex features in the photodissociation spectrum of ${\mathrm{Cs}}_2$ are reproduced well by the close-coupling calculation including three channels. A very narrow resonance with a linewidth of ∼2×${10}^{\mathrm{-}7}$ ${\mathrm{cm}}^{\mathrm{-}1}$ is predicted. It is shown that q reversal can occur in predissociation with only two channels involved.