Charge-displacement analysis of the interaction in the ammonia-noble gas complexes.

We carry out an accurate ab initio study of the interaction between ammonia and the whole series of noble gas atoms and relate the results to those of high-resolution scattering experiments that provide access to the average radial dependence of the interaction potential. The charge-displacement calculations show that charge transfer is a non-negligible, strongly anisotropic, component of the interaction, governing some basic features of the potential energy surfaces especially for the heavier systems. A comparison is made with the analogous binary complexes of H(2)O with the water-H(2) system (Belpassi, L.; et al. J. Am. Chem. Soc.2010, 132, 13046), supporting the conclusion that charge transfer plays a peculiarly special role in water's intermolecular interactions.