Local σ-π mixing in C60 buckminsterfullerene

The local σ-π mixing phenomenon in C60 buckminsterfullerene is quantified. To accomplish this, the localized orbitals spanning the space of fullerene's σ and π systems were orthogonalized and projected onto canonical molecular orbitals. The results show that there exist π-type molecular orbitals which possess ∼10% σ character and vice versa. This strong mixing can be considered as a new evidence that contributes to the unconventional properties of fullerenes. The localized analysis detected bond bending for both σ and π bonds which were deviated from their framework for nearly 14 degrees. Also, several localized aspects of the π system shows two types of π bonds while the σ bonds are fairly equivalent.