  The rate coefficient formulae of unimolecular reactions are generalized to
the systems with the power-law distributions based on nonextensive statistics,
and the power-law rate coefficients are derived in the high and low pressure
limits, respectively. The numerical analyses are made of the rate coefficients
as functions of the nu-parameter, the threshold energy, the temperature and the
number of degrees of freedom. We show that the new rate coefficients depend
strongly on the nu-parameter different from one (thus from a Boltzmann-Gibbs
distribution). Two unimolecular reactions are taken as application examples to
calculate their power-law rate coefficients, which obtained with the
nu-parameters slightly different from one can be exactly in agreement with all
the experimental studies on these two reactions in the given temperature
ranges.
