  The collision theory for power-law distributions and a generalized collision
theory rate coefficient is studied when the reactions take place in
nonequilibrium systems with power-law distributions. We obtain the power-law
rate coefficient and by numerical analyses we show a very strong dependence of
the rate coefficient on the power-law parameter. We find that the power-law
collision theory can successfully overcome the two difficulties of
Lindemann-Christiansen mechanism. We take three reactions as examples to
calculate the pre-exponential factor and yield the values that can be exactly
in agreement with those measured in the experimental studies.
