H2, Ne, and N2 Energies of Encapsulation into C60 Evaluated with the MPWB1K Functional.

The recently suggested MPWB1K functional is tested on H2@C60, Ne@C60, and N2@C60 as a tool for evaluations of stabilization energies upon encapsulation of nonmetallic species into fullerenes. It is found that the MPWB1K (modified Perdew-Wang and Becke functionals) values can be within a few kilocalories per mole from the MP2 or SCS-MP2 (spin-component scaled MP2) values so that further applications of the functional are clearly encouraged. The best estimates of the encapsulation-energy gains found for H2@C60, Ne@C60, and N2@C60 are at least 4 kcal/mol, slightly less than 4 kcal/mol, and about 9 kcal/mol, respectively.