Molecular-orbital decomposition of the ionization continuum for a diatomic molecule by angle- and energy-resolved photoelectron spectroscopy. II. Ionization continuum of NO

Abstract

The quantum-state-specific photoelectron angular distributions (PADs) from the NO A 2Σ+(ν=0, N) and D 2Σ+(ν=0, N) states are analyzed based on the theoretical formalism presented in the preceding companion article. The dynamical parameters in this analysis can be divided into two distinct types, one that directly pertains to the dynamics in the ionization continuum of NO that yields the NO+ X 1Σ+(ν+=0, N+) ion and the other that depends both on the ionizing state and on the ionization continuum. The continuum parameters obtained in this study determine various molecule-frame scattering matrices that describe the short-range collision dynamics between the photoelectron and the NO+ X 1Σ+(ν+=0, N+) core and agree very well with the corresponding quantum-defect quantities determined for high-lying Rydberg states converging to the NO+ X 1Σ+(ν+=0, N+) ion. Specifically, it is found that sσ- and dσ-partial waves mix almost completely because of the anisotropic interactions between the photoelectron and the other electrons in the ion core whereas the orbital angular momentum of the other partial waves are relatively unperturbed by scattering with the ion core. The dynamical parameters determined in the analysis also constitute complete descriptions of the photoionization events of the NO A 2Σ+(ν=0, N) and D 2Σ+(ν=0, N) states and provide detailed quantitative information about the Cooper minimum in the 3pσ→dσ ionization channel that appears in the photoionization of the NO D 2Σ+(ν=0) state. The present study represents the first direct experimental determination of the scattering dynamics between the photoelectron and the ion core in a molecular system.