This plot of computational results for the Kimball model of normal, staggered hydrocarbons C1
C26 has been shown.
P. Politzer (1976) J Chem Phys 64:4239 has used the ratio -(Vne+2*Vnn)/(Vee-Vnn) which varies very slightly for a large range of molecules. It has been widely tested by Snyder & Basch (1972), "Molecular wave functions and properties", Wiley, New York, who found a value of
The plot, above, shows the exact Politzer number for the Kimball hydrocarbons tested.
The molecules shown in the gallery (page above) and a couple more have been tested similarly. The following table depicts the Politzer ratios determined:
The average value of the set of 53 molecules is 6.61 ± 0.54, using the energy components derived by Kimballs model from experimental structures of variable precision.