RRKM/QET calculations

Baer T and Mayer PM (1997) Statistical RRKM/QET calculations in mass spectrometry, journal of the American society of Mass Spectrometry 8 103-115. 

While the statistical RRKM/QET theory was being used to fit fall-off curves and the results of chemical activation studies, its fundamental assumptions were also being tested by classical trajectory calculations, an approach pioneered by Bunker (1962,... 

It has often been naggingly remarked that the RRKM-QET theory can fit anything and predict nothing. To counter this criticism, many authors have multiplied skilful consistency checks (study of isotope effects, preparation of the ion via a bimo-lecular reaction or via charge reversal in addition to electron or photon impact, time-resolved studies all the way from the millisecond to the nanosecond timescales, etc.) and have removed arbitrariness via ab initio calculations of frequencies. However, it should be realized that ability to fit the experiments by no means implies that the theory is exact and that its basic assumptions (full energy randomization and existence of a good transition state) are fulfilled. It has been seen that Equation [1] cannot be grossly in error because of a mechanism of cancellation of errors. In contradistinction, KERDs (for which the cancellation of errors does not work because they basically depend on the numerator only) provide a much better way to test the validity of the... 

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