Comment on "Analytic solution of relaxation in a system with exponential transition probabilities"

The relaxation of a system of highly excited molecules can be described by a reaction/(de)activation master equation. Much work has been concentrated on the functional form of q(x,y), the probability of a reactant molecule starting with energy y and having final energy x after collision with a bathgas molecule. A recent study [J. Chem. Phys. 86, 1269 (1987)] suggests that an exponential q(x,y) is neccessary for linear decay. This Comment shows that such an exponential transition probability is merely sufficient. The linear decay is also predicted by a step-ladder model for q(x,y).