Parametrized direct dynamics study of rate constants of H with CH₄ from 250 to 2400 K

Four implicit potential energy surfaces with specific reaction parameters (SRP) were derived for the reaction CH₄+H→CH₃+H₂ based on hybrid HF density functional theory and multi-coefficient correlation methods. The parametrizations of three of the surfaces were also designed to reproduce the experimental reaction energy, which was estimated from experiment to be 3.3 kcal/mol by using reassessed thermodynamics data for the methyl group.