A Molecular Dynamics Study of the Structure of an Aqueous KCl Solution
A molecular dynamics simulation of a 2.2 molal aqueous KCl solution has been performed using the ST2 water model. The simulation extended over 5ps at an average temperature of 288 K. The basic box has a side length of 18.74 A and contained 200 water molecules, 8 cations and 8 anions. The structure of the solution is discussed by radial distribution functions, the orientation of the water molecules, and their geometrical arrangement in the first hydration shells. The first shells of K+ and Cl- extend up to 3.52 and 3.84 A, respectively, with the corresponding hydration numbers 7.8 and 7.6. The results are compared with recent neutron and X-ray diffraction data and with findings of previous MC and MD simulations using various water-water potentials.