Predicting energies and geometries for reactions involved in atmosphere chemistry: a comparison study between hybrid DFT methods

The energies and geometries of the reactants, transition states and products of 19 reactions involved in atmosphere chemistry are studied using the MPW1K, BH&HLYP and B3LYP hybrid density functional theory (DFT) with the 6-31 + G(d,p) basis set. By comparing to experimental results or high-level calculations we find that the root-mean-square error (RMSE) of energies are 1.7, 2.2 and 2.7 kcal/mol for MPW1K, BH&HLYP and B3LYP methods, respectively. For geometrical parameters, the RMSE of MPW1K and BH&HLYP are close. B3LYP gives the worst estimation among the three DFT methods employed in the present study.