Stabilization of the C20 cage by encapsulation of H+ and He2+ ions

Abstract

It is shown by ab initio calculations using secondorder Møller-Plesset perturbation theory and 6-31g*, aug-cc-pVDZ and aug-cc-pVTZ basis sets and coupled cluster singles, doubles and perturbative triples method with the 6-31g* basis set, that it is possible to stabilize the cage structure of the smallest fullerene C20 by encapsulating small cations like H+ and He2+. While the latter stabilizes the cage structure by charge transfer, the former prefers to form a covalent linkage with the carbon atoms.