Structural and electronic properties of aqueous NaCl solutions from ab initio molecular dynamics simulations with hybrid density functionals

We present a study of a dilute solution (1 M) of NaCl in water, carried out using ab initio molecular dynamics with semilocal and hybrid functionals. We showed that the structural and electronic properties of the solute and the solvent are the same as those obtained in the infinite dilution limit, i.e. for aqueous ions in the presence of a uniform compensating background. Compared to semilocal functionals, simulations with hybrid functionals yield a less structured solution with a smaller number of hydrogen bonds and a larger coordination number for the Cl− anion. In addition, hybrid functionals predict qualitatively correct positions of the energy levels of the ions with respect to the valence band of water.