Utilizing a theoretical method supported by DFT calculations, the options of molecular construction of isomer 17418 (C1) of fullerene C76 with the distribution of single, double and delocalized π-bonds has been decided for the primary time. It’s proven the unconventional nature along with the well-known overstrain resulting from pentalene fragment are the explanations for the instability of this fullerene as empty molecule. The synthesis of endohedral metallofulerenes is accompanied by the formation of an ion pair: the fullerene anion and a metallic cation contained in the molecule. It`s resulting in the closure of the electron shell of the fullerene molecule and the removing of extra native strains. The beforehand experimentally decided cations websites contained in the fullerene, which stabilize the molecule as an entire, are near the disclosed radical clusters.