An analytic representation of the six-dimensional potential energy surface of hydrogen fluoride dimer

We present a semiglobal potential energy surface for HF dimer that should be especially realistic in the vicinity of the two equivalent hydrogen-bonded-complex geometries and the transition state separating them. It is based on fits to 106 correlated calculations and 378 SCF calculations of the energy of the planar complex plus a separate fit to the empirical out-of-plane bending potential of Barton and Howard at a sequence of geometries along the minimum energy path for the degenerate rearrangement connecting the two minima.