“…But since the synthesis of fullerenes takes place at high temperature, the entropy contribution can be quite significant. Slanina et al [3], using a hybrid HJ?/DFT method, showed that even though the D2d isomer is the most stable one at 0 K, the D6h isomer becomes the most stable isomer at temperatures higher than -500 K. The other explanation is based on the exceptionally large electron correlation energy in the D6h isomer [13,14] predicted by a semi-empirical method. Fowler et al [13 J used configuration interaction (CI) calculations, including single and double excitations in the space of the four orbitals (HOMO-1, HOMO, LUMO and LUMO+l), to show that the eIectron correlation effect is significantly larger for the D6h isomer compared to other C36 isomers.…”