A systematic ab initio investigation of the open and ring structures of ozone

The energy difference between the open and the ring isomer of ozone as well as the dissociation energy (O3(X̃, 1A1) → O2(X, 3Σ−g)+O(3P)) have been determined at the CCSD(T), MR-CISD and MR-AQCC levels of theory. Using correlation consistent basis sets up to quintuple-zeta quality, the estimated complete basis set limits for CCSD(T) and MR-AQCC lie within 1 kcal/mol of the experimental value of 26.1±0.4 kcal/mol and place the ring isomer by 4.8 and 5.3 kcal/mol, respectively, above the dissociation limit. Zero-point vibrational corrections increase the latter two values by 1.4 kcal/mol.