Reliable charge assessment on encapsulated fragment for endohedral systems.

A simple scheme to determine charge distribution in endohedral complexes is suggested. It is based on comparison of inner-shell atomic orbital energies of the encapsulated species to the corresponding energies in reference systems with unambiguously defined charges on X. This robust approach is applied to endohedral borospherenes X@B39, for which the conventional schemes provide in some cases quite different results. Efficiency of proposed scheme also has been proven for typical fullerene based Sc3N@C80 endohedral complex.