Semiquantitative Calculations

So far, El transition rates have not been calculated with wavefunctions including octupole deformation. However, semiquantitative calculations performed by Chasman [Ahm84] and Leander [Lea84b] indicate that octupole deformation causes large enhancemets and large fluctuations in El rates. 

J.-K. Hwang and A. Warshel, Biochemistry, 26, 2669 (1987), Semiquantitative Calculations of Catalytic Free Energies in Genetically. Modified Enzymes. 

A semiquantitative calculation of the catalytic efficiency factor is the only way to derive rational criteria for the optimal strategy of a reincubation step. 

Presently we have no exact values for the rate constants of the polymeric reactions (P2)-(P5) however, these measurements are in progress. Also some modifications in the MBM mechanism can be expected 1,4), Nevertheless, the present semiquantitative calculations applying estimated rate constants prove that the assumed mechanism of the polymeric perturbations qualitatively predicts the observed perturbation effects due to the polymers. Simulation results are shown in Figure 4. In Figure 4A Ce(IV) oscillations of the unperturbed BZ system are depicted. The perturbation effect due to the polymer backbone reaction is shown separately in Figure 4B. It causes a shortening of the induction... 

The accurate prediction of electronic transition energies and intensities remains a challenging area of quantum chemistry. Many of the early successes of MO theory involved qualitative interpretations of electronic spectra. The development of the Huckel model made semiquantitative calculations for conjugated organic molecules possible for the first time. The crystal field model (see Chapter 2.35) was successfully applied to calculate d-d transitions in TM complexes. 

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