THE NU(3) INFRARED-SPECTRUM OF THE HE-NH4- REPLY( COMPLEX )

In a recent study, the angular anisotropy of the intermolecular potent ial of the He-NH4+ ionic complex has been estimated using ab initio me thods, In response, Read and Buckingham have calculated the anisotropi c contributions arising from long-range induction and dispersion inter actions and have found near quantitative agreement with the ab initio computations for the energy difference between the vertex-bound and fa ce-bound minima, Thus encouraged, they have predicted minimum structur es for Rg-NH4+ complexes involving heavier rare gas (Rg) atoms and hav e concluded that the face-bound structure becomes more favorable as th e size of the rare gas atom increases, However as discussed here, ab i nitio results for Ar-NH4+ differ from their predictions.