Vibrational predissociation of highly vibrationally excited van der waals molecules: A quantal close‐coupling calculation

In this paper we present numerical calculations of close‐coupling equations to study vibrational predissociation of the T ‐shaped He…I 2 ( B ) van der Waals molecule. In the region of high vibrational excitation of the I 2 subunit, the vibrational predissociation rates are related to the widths of the resulting resonances for the He‐I 2 ( B ) collision. We apply a reasonable approximation to calculate the necessary background S matrix, i.e., the S matrix in absence of resonances. The rates of perpendicular vibrational predissociation, as a function of the initial I 2 vibrational quantum number v 1 , show a maximum at v 1 = 58 almost in agreement with the experimental data. However, an oscillatory and very interesting behavior of the rates in the region 60 ≤ v 1 ≤ 65 is found.