Rotationally resolved photoelectron spectra in resonance enhanced multiphoton ionization of H2O via the C 1B1 Rydberg state

In this paper, we extend a previous formulation of molecular resonance enhanced multiphoton ionization (REMPI) photoelectron spectra of diatomic molecules to treat rotationally resolved photoionization of nonlinear polyatomic molecules. Useful parity selection rules, which govern changes of angular momenta ΔKa and ΔKc, are also derived. As an example, we use this formulation to study rotational branching ratios and photoelectron angular distributions resulting from (3+1′) REMPI of H2O via the C 1B1 (3pa1) Rydberg state. Cooper minima are predicted to occur in the d wave (l=2) of the ka1 (λ=0) and kb1 (λ=1) photoelectron continua. The effects of these Cooper minima on rotationally resolved photoelectron spectra are also investigated.