Theoretical Studies Related to Time Resolved Spectroscopy: The Iterative Rydberg-Klein-Dunham Method and Weyl Theory Applied to the Predissociations in the B2Σ- State of CH

Abstract

The Iterative Rydberg-Klein-Dunham (IRKD) method for the construction of potential energy curves for diatomic molecules is applied to the B2Σ- state of the CH radical. Experimental information form all rovibronic bound states (and even some orbiting resonances) is used. Both spin components, F1 and F2, of the model potential are treated. The resulting curves accurately reproduce the input information and are used to calculate orbiting resonances by means of LeRoy and Bernstein's Airy function boundary condition method (where applicable) and by the Weyl-Titchmarsh-Riccati technique.For the orbiting resonances the calculated linewidths are compared with experimental lifetime measurements and the long range parts of the potential energy curves are adjusted to fit the lifetimes. Finally, an observed interaction between the B2Σ- and A2Δ state is discussed.