Electron structure, geometry and thermochemistry of the cyclic carbon clusters Cn (n = 8, 10, 12)

The results of the quantum chemical study of cyclic C8, C10 and C12 carbon clusters in the B3LYP/aug-cc-pVDZ approximation are presented. For the C8 cluster, two local minima of the D4d and C4h symmetry and the crown-like transition state were found. Atomization energies and thermochemical data (T = 100-5000 K) are tabulated for the title compounds.