Nonadiabatic electron-transfer rate

Activationless maximum at ΔG° = eV
kmax = s⁻¹
Marcus electron-transfer rate versus reaction free energy An interactive curve with normal and inverted Marcus regions and a maximum at minus the reorganization energy.
kET = 2πℏ |HAB|² 1 √(4πλkBT) exp [−(ΔG° + λ)² / (4λkBT)]

Classical Marcus theory with energies in eV; ℏ = 6.5821 × 10⁻¹⁶ eV·s and kB = 8.6173 × 10⁻⁵ eV·K⁻¹.