Journal title:

The Journal of Physical Chemistry A 
Abstract:

Bound energy levels and properties of the Cl((2)p)HF complex were obtained from full threedimensional (3D) calculations, with the use of the ab initio computed diabatic potential surfaces from the preceding paper and the inclusion of spinorbit coupling. For a better understanding of the dynamics of this complex we also computed a 21) model in which the HF bond length r was frozen at the vibrationally averaged values r(0) and r, and a 2 + ID model in which the 3D potentials were averaged over the nu(HF) = 0 and nu(HF) = 1 vibrational wave functions of free HE Also ID calculations were made in which both r and the ClHF distance R were frozen. The complex is found to have the linear hydrogen bonded ClHF structure, with groundstate quantum numbers J = (3)/(2) for the overall angular momentum and IQ I = 3/2 for its projection on the intermolecular axis R. The binding energy is Do = 432.25 cm(1) for VHF = 0 and D0 = 497.21 cm(1) for nu(HF) = 1. Bending modes with vertical bar Omega vertical bar = 1/2 and vertical bar Omega vertical bar = 5/2 are split by the RennerTeller effect, since the electronic ground state is a degenerate (2)Pi state. A series of intermolecular (R) stretch modes was identified. Rotational constants and ef parity splittings were extracted from the levels computed for J = 1/2 to 1/2. The computed red shift of the HF stretch frequency of 64.96 cm(1) and the Cl35Cl37 isotope shift of 0.033 cm(1) are in good agreement with the values of 68.77 and 0.035 cm(1) obtained from the recent experiment of Merritt et al. (Phys. Chem. Chem. Phys. 2005, 7, 67), after correction for the effect of the He nanodroplet matrix in which they were measured.
