Computer simulation of muonium in water

The structure of water molecules surrounding an isolated hydrogen atom (H) or muonium (Mu) is investigated using computer simulation. The water solvent is treated using classical mechanics and a simple effective two body potential that is designed to yield a reasonable solvent structure. Feynman’s path integral approach is used to treat the single quantum impurity (H or Mu). Both the H and Mu atoms are found to be clathrated with average coordination numbers of 18 and 23 water molecules, respectively. The value for the H atom differs little from the results of a purely classical calculation. It is suggested that the lack of isotope effect in certain diffusion controlled reactions of H and Mu is due to the enclathration of both species.