Molecular dynamics computation of the work of ion solvation: comparison of two models of water

Clusters of the TIP4P water model with 125 and 256 molecules and with the K⁺ or K^? ions were simulated by the molecular dynamics method. The radial profiles of local density, energy, normal pressure and molecular orientation were obtained. The work of cluster formation was calculated from the normal pressure profile. The results for the TIP4P and SPC/E model of water are discussed in comparison with each other. A divergence in behaviour of water molecules in the two models was discovered.