Electronic Structure and Stability of Small Cation and Anion Hydrogen Clusters

摘要

Ab initio calculations of the electronic structure of Hn- and Hn+ clusters have been carried out using accurate Gaussian basis sets and with levels of theory up to fourth-order perturbation theory (MP4) and single and double excitation configuration interaction (CISD). The odd hydrogen cation addition sequence, Hn+ + H2 - Hn+2, appears to be thermodynamically stable for large size cluster formation. The even H6+ cation also exhibits surprising stability in D2d symmetry. In contrast, the hydrogen anion addition sequences, Hn- +2dH - Hn-1 and Hn- + H2 - Hn-2, appear to be thermoneutral or unstable.