摘要：

For many years there has been some question whether one should correct for the effects of molecular symmetry, in the rate expressions of transition state theory, by simply using symmetry numbers, as one does in the equilibrium expressions of statistical thermodynamics; several authors have asserted that the correct rate expressions should instead contain "statistical factors", which are dynamically defined numbers characteristic of the reaction mechanism. We show that the use of symmetry numbers is always correct, and that statistical factor rate expressions - when they differ from their symmetry number counterparts - are wrong. Special attention is given to reactions involving optically active species, and to symmetric reactions, where it is easy to make mistakes in writing down transition state theory rate expressions. The implications for the Brnsted relations of acid-base catalysis are discussed.

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