Structure and hydrogen bonding in aqueous sodium chloride solutions using theoretical water model AB4: Effects of concentration

The present work depicts a theoretical study of the influence of Na+ and Cl− ions on the structure and characteristics of the so-called AB4 water model and the corresponding hydrogen bonding phenomenon. Through this model, molecular dynamics simulations are carried out on aqueous NaCl solutions following a concentration range at ambient conditions. ted densities are in very good agreement with the experimental data at concentrations ranging from 1.32 M to 6.61 M. The analysis of radial distribution functions and average coordination numbers in the first solvation shell presents a change in the structure of water by the growth of the average coordination number of oxygen atoms and a reduction of hydrogen bonds population for different concentrations. The ion–water and ion–ion structures are in good correlation with theoretical and experimental results obtained by using different water models. The diffusion coefficients of Na+ and Cl− ions decrease with increasing concentration and become equal for the high concentrations where the two ions diffuse like only one entity. h the results obtained, one can conclude that AB4 model of water is valid and can be used in the theoretical studies of the aqueous solutions.