Rice-Ramsperger-Kassel Marcus treatment

For the rigid entrance/rigid exit complex-forming bimolecular reaction HO + CO — H + CO2, which passes through HOCO, a separated-step conventional Rice-Ramsperger-Kassel-Marcus (RRKM) treatment extremely well reproduces the experimental temperature and pressure dependences of this four-atom system. 

More sophisticated treatments of Lindemann s scheme by Lindemann— Hinshelwood, Rice—Ramsperger—Kassel (RRK) and finally Rice— Ramsperger—Kassel—Marcus (RRKM) have essentially been aimed at re-interpreting rate coefficients of the Lindemann scheme. RRK(M) theories are extensively used for interpreting very-low-pressure pyrolysis experiments [62, 63]. 

In recent years the semiclassical "statistical theory of RICE, RAMSPERGER, KASSEL, and MARCUS /136/ has made great progress in its development. The computational techniques of this theory provide the possibility of calculating the velocities of unimolecular reactions using suitable, models for the activated complex. This approach is certainly very useful for a correlation of the experimental facts and a description of various aspects of the observed phenomena. The success of such applications of the RRKM-theory does not at all preclude an alternative treatment based on the collision theory of... 

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