Dynamics of the O(3P) + CH4 → OH + CH3 reaction is similar to that of a triatomic reaction.

The O((3)P) + CH(4) reaction has been investigated using the quasi-classical trajectory (QCT) method and an ab initio pseudotriatomic potential energy surface (PES). This has been mainly motivated by very recent experiments which support the reliability of the triatomic modeling even at high collision energy ( = 64 kcal mol(-1)). The QCT results agree rather well with the experiments (translational and angular distributions of products); i.e., the ab initio pseudotriatomic modeling "captures" the essence of the reaction dynamics, although the PES was not optimized for high E(col). Furthermore, similar experiments on the O((3)P) + CD(4) reaction at moderate E(col) (12.49 kcal mol(-1)) have also been of a large interest here and, under these softer reaction conditions, the QCT method leads to results which are almost in quantitative agreement with experiments. The utility of the ab initio pseudotriatomic modeling has also been recognized for other analogous systems (X + CH(4)) but with very different PESs.