THE INTERATOMIC STRUCTURE OF ARGON IN WATER

The first order difference method of neutron diffraction and isotopic substitution has been applied to argon dissolved under pressure in heavy water. The results show that argon atoms possess a well-defined nearest neighbor hydration shell composed of 16(2) water molecules in the range 2.8 less than or equal to r (Angstrom) less than or equal to 5.4. Also evident is a weaker second shell which extends to: similar to 8 Angstrom. The results are in broad agreement with those obtained from Monte Carlo and M.D. computer simulation of models in which an argon atom interacts with a number of water molecules via pairwise additive forces. Significant differences are discernible when attempts are made to match quantitatively the theoretical results over the entire range of the experimental information.