Comment on "Theoretical Studies on a Carbonaceous Molecular Bearing: Association Thermodynamics and Dual-Mode Rolling Dynamics" by H. Isobe, K. Nakamura, S. Hitosugi, S. Sato, H. Tokoyama, H. Yamakado, K. Ohno and H. Kono, Chem. Sci., 2015, 6, 2746