A theoretical approach for accurate predictions of the enthalpies of formation of carotenes

A computational approach has been designed for accurately determining enthalpies of formation (ΔH_f) for the carotene species. This approach, named correlation corrected atomization (CCAZ), is based on the concept of bond and group additivity, and is applied along with density functional theory (DFT). Corrections to the deficiencies in DFT were divided into 1,2-, 1,3-, and 1,4- atomic interactions, which were determined by comparisons with the G3 data of the training set. When comparing predictions from CCAZ combined with two different DFT methods (B3LYP and MPWB1K), fairly accurate prediction is expected. In contrast, DFT using the atomization and isodesmic schemes resulted in poor predictions of ΔH_f. The equivalent methods, atomic equivalent (AEQ) and group equivalent (GEQ) provide improved predictions; however, the accuracies are lower than that of CCAZ.