“…Extending the understanding of chemical reactivity at the most detailed level of quantum-state resolution toward increasingly large systems is a subject of fundamental importance. Recent research in this area focuses on reactions of methane with different atoms as prototypical examples. , Impressive progress has been achieved in the experimental studies of X + CH 4 → HX + CH 3 (X = H, F, Cl, and O) reactions and their isotopologues. − The accurate theoretical description of these reactions is still a challenging task. , Reduced-dimensional wave packet dynamics calculations explicitly including seven or eight dimensions were reported for the H + CH 4 ⇆ H 2 + CH 3 reaction and their isotopologues, − the F( 2 P) + CHD 3 → HF + CD 3 reaction, the Cl( 2 P) + CH 4 → HCl + CH 3 reaction and its isotopologues, ,− the O( 3 P) + CH 4 → HO + CH 3 reaction, , and the HBr + CH 3 → Br + CH 4 reaction . Full-dimensional quantum dynamics calculations for these six-atom reactions are even more challenging, and reports are limited to the H + CH 4 → H 2 + CH 3 reaction − and the H + CHD 3 → H 2 + CD 3 reaction. − Almost all full-dimensional calculations employed the quantum transition-state (QTS) framework − and the multiconfigurational time-dependent Hartree (MCTDH) approach , to obtain reaction rates, , initial state-selected reaction probabilities, − ,− and state-to-state reaction probabilities .…”