Hydration of inert solutes. A molecular dynamics study

Molecular dynamics techniques have been used to study the structural changes in the "configuration interaction" model of water resulting from the introduction of several nonpolar, essentially hard-sphere solutes. The use of a high-speed array processor permitted very long (70 ps) simulations of systems of 343 molecules of which 4 are solute molecules. Structural reorganization within the shells surrounding the solutes and a small degree of slowing down of the molecular motions in the shells were observed, in agreement with previous theoretical and experimental work. The question of whether there exists a solvent-induced hydrophobic attraction between the nonpolar solutes was also examined; the simulations failed to reveal any tendency for the solute molecules to aggregate.