Unusual pentagon and hexagon geometry of three isomers (no 1, 20, and 23) of fullerene C₈₄

Three isomers 23 (D 2d ), 1 (D 2 ), and 20 (T d ) of fullerene C 84 have been investigated by PM3, HF/6‐31G*, and DFT methods with B3LYP functional at the 6‐31G and 6‐31G* levels. In this article we reveal for the first time that some distortion of hexagon (pentagon), measured as its maximal dihedral angles, caused by local molecular strains may serve as a new criterion of stability of fullerenes with closed shell.