We have performed molecular dynamics calculations on Cl−(H2O) n and F−(H2O) n (n=2,3,...,15) clusters. The calculations show that the F− ion is solvated in these clusters, while Cl− remains attached to the water in the clusters. We also obtained the minimum energy structures for the Cl−(H2O) n and F−(H2O) n (n=6,7,8) clusters. From the comparison of these structures with the dynamical structures we conclude that the solvation of the F− ion is due to the entropy effect