Enhanced energetic stability and optical activity of symmetry-reduced C60

Quantum chemical calculations establish that small distortions from the perfectly spherical Ih symmetry of C60 to lower symmetries are energetically feasible. A D3d symmetry structure proved to be the lowest energy structure, almost 0.9 kcal/mol lower than the Ih conformation. Activations of otherwise Ih silent modes, the IR Gu at 1465 cm−1, and the Raman Gg around 1530 cm−1 may require the assignments of previously identified combinations modes as fundamentals in the new structure. A recent observation attributing resonance Raman band at 281 cm−1 as due to distortions to either D3d or D5d structures of C60 in solution is discounted.