Experimental rate data for seven organic reactions at cryogenic temperatures have been interpreted to provide information about the dynamics of the reactant molecules in different energy levels. The observed thermal rate constants were assumed to equal sums over quantized energy levels of the specific rate constant for a level multiplied by the Boltzmann population for the level. The model has been analyzed to find relationships between microscopic behavior and experimental observables, such as the isokinetic point, the point of maximum curvature, the activation energy, the pre-exponential factor, and the kinetic heat capacity spectrum. By least squares fitting, the energy gaps between the active levels were found to be 950 +/- 50, 1120 +/- 40, 230 +/- 30, 580 +/- 40, 440 +/- 30, 700 +/- 70, and 630 +/- 50 cm(-1) for the inversions of the oxiran-2-yl and [2-D]-1,3-dioxolan-2-yl radicals, for hydrogen atom transfer in irradiated dimethylglyoxime, tripler 2-(2’-hydroxyphenyl)benzoxazole, and 2- (2’-hydroxy-4’-methylphenyl)benzoxazole, and for deuterium atom transfer in tripler 2-(2’deuteriooxyphenyl)benzoxazole and 2-(2’-deuteriooxy-4’-methylphenyl)benzoxazole respectively. The specific rate constants times the degeneracies of the dominant, excited, reactive levels were 3.8 +/- 0.2, 5.0 +/- 0.1, 2,8 +/- 0.2, 2.8 +/- 0.1, 2.5 +/- 0.1, 4.8 +/- 0.3, and 4.6 +/- 0.2 orders of magnitude, respectively, faster than the corresponding quantities for the lower level. Inversion of the oxiranyl and dioxolanyl radicals may be limited by the rate of vibrational excitation.