Full-potential linear muffin-tin orbital calculation of atomic forces and optimization of atomic structure of fullerene epoxide derivatives C₆₀O and C₆₀O₂

Atomic force calculations and the optimization of atomic structure in the ground state have been made in the cluster version of the full-potential linear muffin-tin orbital method. Relaxation along atomic forces in the ground state enabled us to estimate the main parameters of the atomic structure and total energy in the ground state of fullerene epoxide derivatives C₆₀O and C₆₀O₂, obtained recently in the reaction of C₆₀ with ozone in toluene. We found the C₆₀O isomer, with the oxygen atom bridging the 6,6 carbon bond, to be more stable than that with the oxygen atom bridging the 6,5 bond. The most polar isomer of C₆₀O₂ with the oxygen atoms placed at the same 6,6 ring, is found to have the lowest energy compared with other bridgings of oxygen atoms, in agreement with experimental data.