TY - JOUR

T1 - Violation of microscopic reversibility and the use of reverse quais-classical trajectories for calculating reaction cross sections

AU - Bowman, Joel M.

AU - Schatz, George C.

AU - Kupperman, Aron

PY - 1974/2/1

Y1 - 1974/2/1

N2 - In order to calculate the transition probabilities (or cross sections) for reactive collisions, such as A + BC(ν, j)→ AB(ν′, j) + C, using the quasi-classical trajectory method, one quantizes the internal energy of the reagents and in addition adopts some algorithm for calculating the internal quantum numbers of the products. A serious consequence of this procedure is that the quasi-classical results do not obey microscopic reversibility. It is shown that for the collinear F + H2(ν = 0) → FH(ν = 2, 3)+ H reaction (and its D2 counterpart), the quasi-classical trajectory probabilities for the reverse reaction not only differ substantially from the forward ones but in general are in much better agreement with accurate quantum calculations. A similar situation was found for the collinear H + H2(0) → H2(1) + H reaction. We suggest that in doing quasi-classical calculations, the reverse of the process of interest should also be considered. Comparison of forward and reverse quasi-classical collinear calculations with accurate collinear quantum results could give an indication of whether forward or reverse calculations should be used for the three-dimensional case.

AB - In order to calculate the transition probabilities (or cross sections) for reactive collisions, such as A + BC(ν, j)→ AB(ν′, j) + C, using the quasi-classical trajectory method, one quantizes the internal energy of the reagents and in addition adopts some algorithm for calculating the internal quantum numbers of the products. A serious consequence of this procedure is that the quasi-classical results do not obey microscopic reversibility. It is shown that for the collinear F + H2(ν = 0) → FH(ν = 2, 3)+ H reaction (and its D2 counterpart), the quasi-classical trajectory probabilities for the reverse reaction not only differ substantially from the forward ones but in general are in much better agreement with accurate quantum calculations. A similar situation was found for the collinear H + H2(0) → H2(1) + H reaction. We suggest that in doing quasi-classical calculations, the reverse of the process of interest should also be considered. Comparison of forward and reverse quasi-classical collinear calculations with accurate collinear quantum results could give an indication of whether forward or reverse calculations should be used for the three-dimensional case.

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U2 - 10.1016/0009-2614(74)85282-6

DO - 10.1016/0009-2614(74)85282-6

M3 - Article

AN - SCOPUS:21544475214

VL - 24

SP - 378

EP - 380

JO - Chemical Physics Letters

JF - Chemical Physics Letters

SN - 0009-2614

IS - 3

ER -