State-to-state ArHBr photodissociation quantum dynamics

We report quantum dynamical calculations on the photodissociation process: ArHBr+hnu-->H+ArBr or Ar+Br+H. Jacobi coordinates associated with the product arrangement H+ArBr have been used as well as a pseudospectral wave packet propagation method. The radial singularity at the origin is either analytically lifted with a discrete Bessel transform approach, or treated within a sine transform strategy. The relative fraction of a bound ArBr product state is high (of the order of 50%) and decreases with energy. Product vibrational populations decrease with vibrational energies. Rotational distributions show oscillatory patterns characteristic of rotational rainbows, whereas angular distributions have maxima at rainbow angles. (C) 2002 American Institute of Physics.