The unimolecular dissociation of the OH stretching states of HOCl: Comparison with experimental data

The unimolecular dissociation of the (v(1),0,0) pure OH stretching states o f hypochlorous acid (HOCl) in the ground electronic state is investigated f or v(1)=6-9. The dynamics calculations are performed on an accurate potenti al energy surface and employ filter diagonalization in connection with an i maginary absorbing potential. The dependence of the linewidth (or dissociat ion rate) on the total angular momentum is emphasized. Resonance enhancemen ts due to mixings with other vibrational states, which have substantially l arger rates, are clearly observed-in qualitative agreement with recent meas urements. The average width increases, in quantitative agreement with exper iments, by four orders of magnitude, from 10(-4) cm(-1) for v(1)=6 to about 1 cm(-1) for v(1)=9. (C) 2001 American Institute of Physics.