Spectrum and vibrational predissociation of the HF dimer. I. Bound and quasibound states

We present full six-dimensional calculations of the bound states of the HF dimer for total angular momentum J50,1 and of the quasibound states for J50 that correspond with vibrational excitation of one of the HF monomers, either the donor or the acceptor in the hydrogen bond. Transition frequencies and rotational constants were calculated for all four molecular symmetry blocks. A contracted discrete variable representation basis was used for the dimer and monomer stretch coordinates R ,rA ,rB ; the generation of the monomer basis in the dimer potential leads to significantly better convergence of the energies. We employed two different potential energy surfaces: the SQSBDE potential of Quack and Suhm and the SO-3 potential of Klopper, Quack, and Suhm. The frequencies calculated with the SO-3 potential agree very well with experimental data and are significantly better than those from the SQSBDE potential. © 2003 American Institute of Physics. @DOI: 10.1063/1.1577111#