Ab Initio Study of Potassium Ion Clusters of Methanol and Acetonitrile and a Systematic Comparison with Hydrated Clusters

摘要

Ab initio calculations of the structure and binding energies of K↑(+)[Solv]↓(n) clusters are reported for water, methanol, and acetonitrile solvents, for n = 1-6. It has been shown that the results obtained at the RHF/ DZP//RHF/DZP level of calculation, with no basis set superposition or correlation correction, compare well, in the case of water, with other accurate treatments in the literature. A comparison of the binding energies and structures of the clusters in the three solvents is made. The enthalpies and entropies of formation of the clusters are calculated and compared with the results of experimental measurements on gas-phase clusters. An analysis of the contributions of the ion-solvent and solvent-solvent interactions to the binding energies is also presented.