Structures and Spectroscopic Properties of Hydrated Zinc(II) Ion Clusters [Zn2+(H2O)n (n = 1−8)] by Ab Initio Study

Global search on small hydrated zinc(II) clusters [Zn2+(H2O)n (n = 1–8)] is executed based on comprehensive genetic algorithm with density functional theory. The subsequent high level ab initio calculation provides accurate structures, energies and spectroscopic properties of the clusters. For n ≤ 6, all the water molecules are coordinated waters in global minima, while two five-coordinated structures possesses the lowest energies for n = 7 and 8 at 0 K. Besides, the four-coordinated structures could equally populate with the global minima above room temperature for n = 5 and 6. Furthermore, the infrared (IR) spectra with anharmonic correction could reproduce the experimental spectra quite well, and effectively discriminate the isomers in experiment, which might be selected by the energetic driving of water-loss reaction.