Laboratory of Physical Chemistry, ETH Zurich, 8093 Zurich, Switzerland.
J Chem Phys. 2018 Mar 14;148(10):102311. doi: 10.1063/1.5001116.
We apply the newly derived nonadiabatic golden-rule instanton theory to asymmetric models describing electron-transfer in solution. The models go beyond the usual spin-boson description and have anharmonic free-energy surfaces with different values for the reactant and product reorganization energies. The instanton method gives an excellent description of the behaviour of the rate constant with respect to asymmetry for the whole range studied. We derive a general formula for an asymmetric version of the Marcus theory based on the classical limit of the instanton and find that this gives significant corrections to the standard Marcus theory. A scheme is given to compute this rate based only on equilibrium simulations. We also compare the rate constants obtained by the instanton method with its classical limit to study the effect of tunnelling and other quantum nuclear effects. These quantum effects can increase the rate constant by orders of magnitude.
我们将新推导出的非绝热黄金定则瞬时理论应用于描述溶液中电子转移的不对称模型。这些模型超越了通常的自旋-玻色子描述，具有不同反应物和产物重组能的非谐自由能表面。瞬时方法极好地描述了速率常数随不对称性的行为，研究范围广泛。我们基于瞬时的经典极限，推导出了马库斯理论的一个不对称版本的通用公式，并发现这对标准马库斯理论有显著的修正。我们给出了一个仅基于平衡模拟来计算此速率的方案。我们还比较了瞬时方法与其经典极限得到的速率常数，以研究隧穿和其他量子核效应的影响。这些量子效应可以使速率常数增加几个数量级。
