Seeding studies on the nucleation of NaCl in supersaturated solutions

It is known that the simulation of rare events, such as the appearance of a nuclei in the heart of a liquid, usually requires special methods that artificially accelerate the crystallization without altering the real nucleation mechanism. Nevertheless, these methods are generally computationally expensive. In the seeding method a seed of the crystal phase is inserted into the systems in order to determine the conditions at which the cluster is critical. Hence, this technique allows to estimate the sizes of the critical cluster in a relatively simple and efficient way. Moreover, when used along the classical nucleation theory and an educated choice of the order parameter, employed to distinguish fluid and solid particles, it can provide good estimates of the nucleation rate at relatively low computational cost.

In this work we used the JC/SPC/E force field to study sodium chloride nucleation from supersaturated aqueous solution, at 1 bar and 298.15 K. It will be shown that nucleation rates obtained from the seeding technique along with the mislabeling criterium, agree reasonably well with those obtained from more rigorous techniques as forward flux sampling.