Approximate method for calculation of electron transition probability for simple outer-sphere electrochemical reactions

The probability of an elementary act in an outer-sphere electrochemical electron transfer reaction is calculated with arbitrary values of the parameter of reactant-electrode electron interaction for diabatic free-energy surfaces of the parabolic form. The dependence of effective transmission coefficient on the Landau-Zener parameter is found. Interpolation formulas are obtained that describe this dependence and allow calculating the electron transition probability using the results of quantum chemical calculations of the electronic matrix element as a function of distance.