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

The unimolecular dissociation of the (v[sub 1],0,0) pure OH stretching states of hypochlorous acid (HOCl) in the ground electronic state is investigated for v[sub 1] = 6–9. The dynamics calculations are performed on an accurate potential energy surface and employ filter diagonalization in connection with an imaginary absorbing potential. The dependence of the linewidth (or dissociation rate) on the total angular momentum is emphasized. Resonance enhancements due to mixings with other vibrational states, which have substantially larger rates, are clearly observed—in qualitative agreement with recent measurements. The average width increases, in quantitative agreement with experiments, by four orders of magnitude, from 10&sup-4; cm&sup-1; for v[sub 1] = 6 to about 1 cm&sup-1; for v[sub 1] = 9. [ABSTRACT FROM AUTHOR]