The photoionization and photodissociation of CH in the vicinity of the ionization threshold

Abstract

The Stieltjes-imaging method is applied to the spectrum of CH which is computed by SCF-MO-CI calculations on single excitation series. The calculations use basis sets of up to 50 Slater atomic orbitals. The continuum cross sections obtained are lower than the previous results of Walker and Kelly who used a perturbation theoretical approach. Our computations indicate strong Rydberg series converging to the ground state and the excited states 3Π and 1Π of CH+. If these Rydberg states were predissociated then the dissociation rate of interstellar CH would be an order of magnitude higher than anticipated. We tentatively derive oscillator strengths for the individual states of the Rydberg series converging to 1Σ + observed by Herzberg and Johns. © 1978 American Institute of Physics.