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

Abstract

We report on our studies of the structural properties of a hydrogen molecule dissolved in liquid water. The radial distribution function, coordination number and coordination number distribution are calculated using different representations of the interatomic forces within molecular dynamics (MD), Monte Carlo (MC) and ab initio molecular dynamics (AIMD) simulation frameworks. Although structural details differ in the radial distribution functions generated from the different force fields, all approaches agree that the average and most probable number of water molecules occupying the inner hydration sphere around hydrogen is 16. Furthermore, all results exclude the possibility of clathrate-like organization of water molecules around the hydrophobic molecular hydrogen solute.

Keywords:

• Hydrophobic hydration
• Hydrogen
• Clathrate hydrate
• Coordination number

PACS numbers:

• 82.20.Wt
• 02.60.Pn

Acknowledgement

The authors would like to thank Randall Cygan and Todd Alam for helpful discussions and critical reading of the manuscript. This work was supported by the LDRD program under Contract DE-AC04-94Al85000. Sandia is a multiprogram laboratory operated by Sandia Corporation, a Lockheed Martin Company, for the US Department of Energy.

Notes

^§Email: [email protected]

Additional information

Notes on contributors

S. B. Rempe

§ §Email: [email protected]