WOLFGANG QUAPP  & ALRAUNE ZECH

Transition State Theory with Tsallis Statistics

for: Journal of Computational Chemistry


abstract:

We discuss the rate of an elementary chemical reaction.
We use the reaction path and especially its saddle point on
the potential energy surface. The reaction path connects reactant
and product of a reaction over the transition state (TS).
Usually, the TS is assumed near or at the single saddle point of the
reaction path.
By means of comparison of the statistics of states at the reactant and
at the TS, one can estimate the reaction rate by the Eyring theory.
We propose to use the Tsallis statistics at the TS, a statistics of
seldom accidents. Thus, we propose to generalize the well known
Boltzmann-Gibbs statistics which is the limiting case of the Tsallis
statistics.
We use features of this non-extensive thermostatistics.
The basic properties of the statistics are employed to derive
(approximated) partition functions, and they are applied on reaction rates.
The approximation includes a factorization of the partition functions.
The theory is applied to HCN isomerization to HNC, and to the reaction
H_2+CN --> H+HCN. It allows an accordance with experimental
estimations of the reaction rates.