EMPLOYING DIFFUSION MONTE CARLO IN THE CALCULATION OF MINIMIZED ENERGY PATHS OF THE CH_(3)~(+) + H_(2) <-> CH_(5)~(+) <-> CH_(3)~(+) + H_(2) REACTION AND ITS ISOTOPIC VARIANTS

摘要

Protonated methane is presumed by astrochemists to be an important intermediate in the reaction CH_(3)~(+) + HD -> CDH_(4)~(+) -> CH_(2)D~(+) + H_(2) within the interstellar medium. Understanding this reaction can also help shed light on the observed nonstatistical H/D isotopic abundance in the isotopologues of CH_(3)~(+) within the interstellar medium. Interestingly, based on kinetic studies, Gerlich and co-workers showed that all of the reactions in the series CH_(3-n)D_(n)~(+) + HD -> CH_(4-n)D_(n+1)~(+) -> CH_(2-n)D_(n+1)~(+) + H_(2) have identical net rate constants. This result is independent of the value of n.