Total and partial decay widths in vibrational predissociation of HF dimer

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 v₂⁺ and v₂^- ("bound- H") excitation, and 11 ns for both v₁⁺ and _v1^- ("free-H") excitations. These theoretical lifetimes are compared to the experimental values of about 1 ns for the v₂ excitation and about 20 ns for the v₁ 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)].