A molecular dynamics simulations study on the modification of aqueous solution structure and dynamics in presence of monovalent salts: An electronic continuum correction approach and effect of ion size

Abstract

The hydrogen bonding structure and dynamics of water are investigated by varying the concentrations up to 6.18 m for full-charged and the electronic continuum correction with rescaling (ECCR) charged model for NaCl solutions using classical molecular dynamics simulations. We have also considered the seven different (MCl/NaX) salt solutions at 6.18 m with varying monovalent cations (M+) or anions (X-). The first and second solvation shells of water in both full- and ECCR models are affected by NaCl concentrations, and destruction of the tetrahedral network structure is observed. Probability of ion pair formation is higher in KCl and NaF solutions compared to other salts at 6.18 m. The self-diffusion coefficient values of water, Na+ in full-charged, and Cl− in ECCR models are in good agreement with the experimental results. The hydrogen bond lifetime of water does not significantly change with increasing NaCl salt concentrations, but Cl−-water lifetime is significantly lowered in the ECCR model.