Marcus Theory:
Electron Transfer
Reorganization energy λ (eV)
1.00
Driving force ΔG° (eV)
-0.50
Electronic coupling H_DA (eV)
0.05
Temperature T (K)
300
Barrier ΔG‡
—
Rate k_ET (s⁻¹)
—
ln(k_ET)
—
Regime
—
Normal region
Marcus (1956, Nobel 1992):
k_ET = (2π/ℏ)|H_DA|²/√(4πλk_BT) · exp[−(ΔG°+λ)²/(4λk_BT)]
Barrier:
ΔG‡ = (ΔG°+λ)²/(4λ). Rate increases with |ΔG°| until ΔG°=−λ (barrierless), then decreases:
inverted region
.