Molecular Dynamics Simulations of Dimethyl Sulfoxide and Dimethyl Sulfoxide−Water Mixture

Abstract

Constant-pressure constant-temperature MD simulations at ambient conditions have been carried out to evaluate three different potential models for DMSO, both as pure liquid and in the (1:3) DMSO−H2 O mixture, based on structural, thermodynamical, and dynamical properties. All the three models for DMSO: OPLS, P2, and NPS, the last one proposed by us, gave a good description of liquid DMSO. In combination with the SPC/E and TIP3P water models, these three potential functions were applied to predict excess mixing functions, reorientational correlation times and diffusion coefficients of the (1:3) DMSO−water binary system. Results obtained with the P2 and NPS models in combination with the SPC/E model for water agreed better with experiment than the OPLS model with either TIP3P or SPC/E water. The new NPS potential model was further used for an analysis of the spatial solvation structure around DMSO in the 1:3 mixture of DMSO− water, based on pairwise spatial distribution functions of atomic number densities...