Theory of electronic branching in the photodissociation of HI and DI

Abstract

Potential curves, nonadiabatic couplings, and transition dipoles of the first four (³Π₁, ¹Π₁,³Π₀, and ³∑₁) excited electronic states of HI are extracted from various photodissociation experiments of HI in the near UV. Excellent agreement with these experiments regarding the overall absorption spectrum, the I*(²P_1/2)/I(²P_3/2) branching ratio, and the β anisotropies of the two channels at various wavelengths, has been achieved. On the basis of the electronic parameters thus extracted, the full dynamics of the HI photodissociation at all excitation energies in the near UV have been unravelled. The data obtained for HI is used to predict the photodissociation dynamics of DI. These predictions are in good agreement with available experimental results. Subsequent work will deal with prediction of the resonance Raman scattering of HI/DI and the control of the I*(²P_1/2)/I(²P_3/2) branching ratio by elliptical control using the Asaro–Brumer–Shapiro scheme.