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Reaction:   H₂S₂ + SH → H₂S + HSS
Reaction order:   2
Temperature:   873 - 1423 K
Pressure:  4.00E-2 - 3.00 bar
Rate expression:   2.51x10^-13 [cm³/molecule s] (T/298 K)^2.98 e^{6192 [J/mole]/RT}
Category:  Theory
Data type:   Transition state theory
Comments:   Rate constants are based on G2 calculations for molecular geometries, energies, and vibrational frequencies of reactants, products, intermediates, and transition states. Master equation RRKM calculations were used to predict pressure dependencies and QRRK analyisis for chemically activated processes. The complete active space SCF (CASSCF) method was used in conjunction with the 6-31G(d) basis set to obtain molecular geometries and vibrational frequencies when multiconfigurational effects were found to be important. The authors validated their 21 step mechanism by comparison with a variety of experimental data from the literature.

The temperature and pressure ranges of validity were not specifically indicated by the authors but are assumed to cover the range experimental data for which the mechanism was validated.

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Rate constant values calculated from the Arrhenius expression: