Propensity of heavier halides for the water/vapor interface revisited using the Amoeba force field

Molecular dynamics simulations of aqueous sodium halide solutions in slab geometry were performed using the state-of-the-art polarizable Amoeba force field. The present calculations reveal a propensity of halide anions for the water/vapor interface, which correlates with the ionic size and polarizability and, therefore, increases in the series Cl− < Br− < I−. These results are in a quantitative agreement with previous calculations employing much simpler polarizable potentials and are supported by a mounting experimental evidence from photoelectron and non-linear optical and vibrational spectroscopies.