Effect of Temperature on Radiationless Transitions

The temperature dependence of the transition probability of radiationless transitions has been discussed by using the golden rule expression for the radiationless transition probability derived from the view‐point of the nonstationary character of the Born—Oppenheimer adiabatic approximation. It is shown that the rate constant of radiationless processes depends on temperature as $$k_{\mathrm{nr}}{\mathrm{/k}}_{\mathrm{nr}}^0\text{=1 +}{\displaystyle \sum _k}{A}_k\hspace{0.17em}\exp {\mathrm{(-\; \hslash \; \omega }}_k^{\prime }\mathrm{/kT).}$$ A_k 's have been shown to be related to the changes in normal coordinates and frequencies in the equilibrium configuration of the two electronic states in which the radiationless transition takes place.