Reply to the comment on “The ν3 infrared spectrum of the HeNH4+ complex”

In a recent study, the angular anistropy of the intermolecular potential of the HeNH4+ ionic complex has been estimated using ab initio methods. In response, Read and Buckingham have calculated the anisotropic contributions arising from long-range induction and dispersion interactions and have found near quantitative agreement with the ab initio computations for the energy difference between the vertex-bound and face-bound minima. Thus encouraged, they have predicted minimum structure for RgNH4+ complexes involving heavier rare gas (Rg) atoms and have concluded that the face-bound structure becomes more favorable as the size of the rare gas atom increases. However as discussed here, ab initio results for ArNH4+ differ from their predictions.