State of hydrogen molecules confined in C_(60) fullerene and carbon nanocapsule structures

摘要

The combination of PM3 semi-empirical method for geometry optimization, and ab initio DFT (density functional theory) for energy calculation, is used to study the configurations of hydrogen molecules at 0 K within the vacuum of C_(60) fullerene and carbon nanocapsules. The obtained structural information including the molecular arrangement and structural state of the clusters of H_2 are mainly determined by two kinds of repulsive energies, namely that between the H_2 molecules and the wall of the spheroidal or capsule like carbon structure, and that between interacting H_2 molecules. It is further established that the repulsive energy among the H_2 molecules is not purely a function of the number of encapsulated H_2, and there is a tradeoff between the two kinds of repulsive energies.