Variation of the resonance width of HOCl(6νOH) with total angular momentum: Comparison between ab initio theory and experiment

Complex L2 calculations of the variation of (very narrow) resonance widths of the 6νOH state of HOCl with total angular momentum are reported, using a recently developed, accurate ab initio potential energy surface [S. Skokov, J. M. Bowman, and K. A. Peterson, J. Chem. Phys. 109, 2662 (1998)]. The calculations are carried out within the adiabatic rotation approximation for the overall rotation and a truncation/recoupling method for the vibrational states. Comparisons with recent double-resonance experiments of the Rizzo and Sinha groups are made. The variation of resonance width with J for K=0 is shown to be due to rotation-induced coupling of the 6νOH state with a dense set of states with large excitation in the dissociative coordinate.