On the microscopic structure of liquid water

Aurélien Perera (1)

1 LPTMC - Laboratoire de Physique Théorique de la Matière Condensée

Abstract The radial distribution function of liquid water, as obtained by the computer simulations of several classical models of water, is re-examined herein and shown to displays two intriguing features. These consist in a compact "three-peaks structure" over three molecular diameters, which is followed by an apparent loss of the packing correlations beyond R_{c}\approx 9 Å. This is in contrast with simple liquids for which the correlations decay continuously with distance. This structure is reproduced for many widely used classical force fields models of water and by scattering experiments as well. It is also preserved in aqueous binary mixtures of organic solvents, even up to equimolar mixture in some cases. The analysis of the structure factor highlights the role played by the competition between packing effect and the Hydrogen bonding interactions. This analysis, in terms to competition of two length scales, is also supported by a simple core-soft model, that reproduces the structural features outlined above.

Mots clés: Physical Sciences

Domaines: Matière Condensée [cond-mat]

Aurélien Perera. On the microscopic structure of liquid water. Molecular Physics, 2011, pp.1. ⟨10.1080/00268976.2011.617712⟩. ⟨hal-00739204⟩