Calculation and Application for the Tunneling-and-Curvature Involved Thermal Rate Constants

Based on the relationship between microcanonical assembly and canonical assembly,the tunnelingand-curvature involved formula k_QM (T) for the unimolecular thermal rate constants is derived in terms ofthe cunulative reaction probability. The rate constants for the hydrogen transfer reaction in HCCF (Ⅰ) and the fluoro transfer reaction in FCCF (Ⅱ) are calculated by the computational program written by us. The results show that,in low temperature(or low energy), both tunneling and curvature correction have obvious influence on the rate constants only for the reaction (Ⅰ). When the temperature (or energy) increase,the rate constants are less influenced by both effects. Besides the fact that our method saves much calculation and computational time, its results are close to that obtained by Polyrate program.