Figure 4.

(A) The structure closest to the reactant of alkane radical with oxygen in the double state (when distance between O₂₁ and C₄ is the farthest during the relaxed scan); (B) the spin density of the structure in (A); (C) the spin density of the structure after the geometry optimization of the lowest energy point structure during the relaxed scan (this is a reflexive reaction with no transition state); (D) the result of the relaxed scan illustrates the change of the total energy along with the distance between O₂₁ and C₄.