MOLECULAR-DYNAMICS STUDY OF AN AQUEOUS LIF SOLUTION

The structure and properties of a 1.791 molal aqueous LiF solution is investigated by performing molecular dynamics simulations using a water model with both bond flexibility and instantaneously responsive polarization. On average, each cation is in close contact with about one anion. This causes a strong overlap of the hydration shells and an almost complete breakdown of the surrounding water structure. While the lone pairs of the hydration waters in the first Li+ shell occupy preferentially tetrahedral positions, the orientational distribution of the solvent molecules around F- is quite uniform. By comparing various autocorrelation functions of water molecules in the solution and in the pure liquid, the influence of solvated ions on the translational, rotational and vibrational motions of hydration water can be studied.