Total and partial decay widths in vibrational predissociation of HF dimer

Abstract

Coupled channel golden-rule quantum mechanical calculations of total and partial decay widths are reported for vibrational predissociation of HF dimer. In this calculation, an ab initio potential energy surface is employed in both bound and scattering calculations but the vibrational coupling is given by an electrostatic interaction. The computed lifetime of HF dimer is 4.0 and 4.8 ns for ν2+ and ν2− (‘‘bound-H’’) excitation, and 11 ns for both ν1+ and ν1− (‘‘free-H’’) excitations. These theoretical lifetimes are compared to the experimental values of about 1 ns for the ν2 excitation and about 20 ns for the ν1 excitation. We also present rotational state distributions of HF monomers which are in qualitative agreement with the experimental measurement of Bohac et al. [J. Chem. Phys. 96, 6681 (1992)].