The kinetics of nonadabatic trapping models of CH~4+H=CH~3+H~2 was studied. On the basis of the Intrinsic Reaction Coordinate (IRC) and IRC information computed by the ab initio method at QCISD/6-311g^*^* level, the flux integrals for collinear system and thermal system of the title reaction were calculated, respectively. The results show that the collinear system of the title reaction is a nonadiabatic trapping model but the thermal reaction is not. Using unified statistical theory (UST) and microcanonical variational transition state theory, rate constants were calculated. The thermal rate constants from 300K to 1500K are in excellent agreement with the experiment results.

Key words: METHANE, HYDROGEN, IRC