cathodic transfer coefficient, \(\alpha_{\text{c}}\)
For a reaction with a single rate-determining step \[\frac{\alpha _{\text{c}}}{\nu } = -\frac{R\ T}{n\ F}\ (\frac{\partial (\ln (|I_{\text{c}}|))}{\partial E})_{T,p,c_{i},...}\] where αc is the cathodic transfer coefficient (number), R is the gas constant, T is the thermodynamic temperature, and ν the stoichiometric number giving the number of identical activated complexes formed and destroyed in the completion of the overall reaction as formulated with the transfer of n electrons.
PAC, 1974, 37, 499. 'Electrochemical nomenclature' on page 515 (