Physical Sciences Division, Pacific Northwest National Laboratory, Richland, Washington 93352, USA.
J Chem Phys. 2013 Aug 28;139(8):084506. doi: 10.1063/1.4819135.
To enhance our understanding of the mechanism of water-exchange around aqueous Li(+), we carried out a systematic study on this system using molecular dynamics simulations with polarizable potential models. The mechanistic properties associated with the water-exchange process, such as potentials of mean force, time dependent transmission coefficients, and the corresponding rate constants, were examined using transition rate theory, the reactive flux method, and Grote-Hynes treatments of the dynamic response of the solvent. We compared the computed rate theory results with results from previous corresponding studies in which classical non-polarizable force fields were used. Our computed barrier heights for water exchange are significantly larger than those obtained using classical non-polarizable force fields. We also studied the effect of pressure on water-exchange rates and the corresponding activation volume. Our computed rate results for water exchange increase with pressure; therefore, a small negative activation volume is observed.
为了增进我们对水在锂离子周围交换机制的理解，我们使用具有极化势能模型的分子动力学模拟对该体系进行了系统研究。使用过渡态理论、反应通量法和溶剂动态响应的 Grote-Hynes 处理方法，研究了与水交换过程相关的力学特性，如平均力势、时变传输系数和相应的速率常数。我们将计算的速率理论结果与以前使用经典非极化力场进行的相应研究的结果进行了比较。我们计算的水交换的势垒高度明显大于使用经典非极化力场得到的结果。我们还研究了压力对水交换速率和相应的活化体积的影响。我们计算的水交换速率结果随压力增加而增加，因此观察到一个较小的负活化体积。
