Limitations of Variational Transition State Theory for Barrierless Radical-Radical Recombination Reactions

Verfasser / Beitragende:
[Jürgen Troe]
Ort, Verlag, Jahr:
2004
Enthalten in:
Zeitschrift für Physikalische Chemie/International journal of research in physical chemistry and chemical physics, 218/4/2004(2004-04-01), 457-468
Format:
Artikel (online)
ID: 378913670
LEADER caa a22 4500
001 378913670
003 CHVBK
005 20180305123548.0
007 cr unu---uuuuu
008 161128e20040401xx s 000 0 eng
024 7 0 |a 10.1524/zpch.218.4.457.29195  |2 doi 
035 |a (NATIONALLICENCE)gruyter-10.1524/zpch.218.4.457.29195 
100 1 |a Troe  |D Jürgen 
245 1 0 |a Limitations of Variational Transition State Theory for Barrierless Radical-Radical Recombination Reactions  |h [Elektronische Daten]  |c [Jürgen Troe] 
520 3 |a Variational transition state theory (VTST) is widely used for the modelling of barrierless radical–radical recombination reactions. In this application, VTST suffers from a number of limitations some of which are of more technical, others of more fundamental nature. The former are caused by inappropriate averaging over individual adiabatic channel potentials or by the neglect of quantum effects, the latter are due to deviations from adiabatic dynamics. It is shown that most radical–radical recombination reactions are characterized by Massey parameters which are smaller than unity such that the dynamics is nonadiabatic. VTST treatments which generally assume adiabatic dynamics, therefore, have a fundamental problem. Calculations of rate constants by VTST often exceed classical trajectory results by about 10 to 20percent. This is normally attributed to "recrossing trajectories”. In the present work it is shown, however, that deviations of this magnitude also have to be expected for nonadiabatic dynamics in comparison to adiabatic dynamics. It is, therefore, suggested that "recrossing” at least in part has to be attributed to nonadiabatic dynamics. A way out of the dilemma is the use of a combination of statistical adiabatic channel and classical trajectory concepts. 
540 |a © 2004 Oldenbourg Wissenschaftsverlag GmbH 
690 7 |a Thermodynamics & statistical physics  |2 nationallicence 
690 7 |a Laboratory techniques, experiments  |2 nationallicence 
690 7 |a Physical chemistry  |2 nationallicence 
773 0 |t Zeitschrift für Physikalische Chemie/International journal of research in physical chemistry and chemical physics  |d Oldenbourg Wissenschaftsverlag GmbH  |g 218/4/2004(2004-04-01), 457-468  |x 0942-9352  |q 218:4/2004<457  |1 2004  |2 218  |o zpch 
856 4 0 |u https://doi.org/10.1524/zpch.218.4.457.29195  |q text/html  |z Onlinezugriff via DOI 
908 |D 1  |a research article  |2 jats 
950 |B NATIONALLICENCE  |P 856  |E 40  |u https://doi.org/10.1524/zpch.218.4.457.29195  |q text/html  |z Onlinezugriff via DOI 
950 |B NATIONALLICENCE  |P 100  |E 1-  |a Troe  |D Jürgen 
950 |B NATIONALLICENCE  |P 773  |E 0-  |t Zeitschrift für Physikalische Chemie/International journal of research in physical chemistry and chemical physics  |d Oldenbourg Wissenschaftsverlag GmbH  |g 218/4/2004(2004-04-01), 457-468  |x 0942-9352  |q 218:4/2004<457  |1 2004  |2 218  |o zpch 
900 7 |b CC0  |u http://creativecommons.org/publicdomain/zero/1.0  |2 nationallicence 
898 |a BK010053  |b XK010053  |c XK010000 
949 |B NATIONALLICENCE  |F NATIONALLICENCE  |b NL-gruyter