Structure of NaCl and KCl concentrated aqueous solutions by ab initio molecular dynamics

We compare the microscopic structure of concentrated aqueous solutions of sodium and potassium chloride obtained using different, rigid charge, intermolecular potentials with those calculated in ab initio simulations. We see that pair correlation functions provide a more severe test than simpler averages like thermodynamic properties, where positive and negative contributions can cancel out even large deviations. The potential models investigated here, in particular, do not provide a consistent picture of the structure of the solution, shedding some doubts on their use within simulation of biological systems.