Improved modelling of atom–molecule potential-energy surfaces: illustrative application to He–CO

The need for better potential-energy models for atom–molecule and molecule–molecule interactions is discussed and the utility of the exchange–coulomb (XC) model is critically examined, by fitting a potential based on it to new high-resolution discrete infrared data for the He–CO Van der Waals molecule. In addition to explaining the observed spectrum as well as does an optimized empirical potential previously determined from the same data, the resulting XC surface is expected to be more realistic in regions not directly sampled by the fitted data.