Molecular studies of the structural properties of hydrogen gas in liquid water

The structural properties of a hydrogen molecule dissolved in liquid water were studied. The radial distribution function, coordination number, and coordination number distribution were calculated using different representations of the interatomic forces within molecular dynamics, Monte Carlo, and ab initio molecular dynamics simulation frameworks. Although structural details differ in the radial distribution functions generated from the different force fields, all approaches agreed that the average and most probable number of water molecules occupying the inner hydration sphere around hydrogen was 16. All results excluded the possibility of local clathrate-like organization of water molecules surrounding the hydrophobic molecular hydrogen solute. This study is a starting point for future studies of hydrogen occupancy of hydrogen clathrate hydrate and its stability. This is an abstract of a paper presented at the AIChE Annual Meeting (San Francisco, CA 11/12-17/2006).