An improved multistate empirical valence bond model for aqueous proton solvation and transport.
An improved multistate empirical valence bond model for aqueous proton solvation and transport.
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DOI：
10.1021/jp076658h
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发表时间：
2008-01
期刊：
影响因子：
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通讯作者：
Yujie Wu;Hanning Chen;Feng Wang;F. Paesani;G. Voth
中科院分区：
文献类型：
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作者：
Yujie Wu;Hanning Chen;Feng Wang;F. Paesani;G. Voth
提出了一个新的适用于水溶液中质子溶剂化和迁移的多状态经验价键模型（MS-EVB 3）。新模型及其量子版本（qMS-EVB 3）基于MS-EVB 2模型[Day等人，J.Chem.Phys.2002，117，5839]和最近开发的柔性水模型-SPC/Fw模型[Wu等人，J.Chem.Phys.2006，124，24503]和qSPC/Fw模型[Paesani等人，J.Chem.Phys.2006，125，184507]-分别用于经典和量子模拟。使用从头算数据作为基准，结合能和优化的几何结构与质子化水簇的新模型计算，以及质子穿梭在水分子在集群环境中的势能面，相比MS-EVB 2模型得到了改善。对于水溶液，经典和量子分子动力学模拟与MS-EVB 3模型产生更准确的描述的溶剂化结构和扩散动力学的过剩质子。还对水中的质子溶剂化和跳跃动力学以及水合质子的“两亲性”性质提供了新的见解，已经预测水合质子的“两亲性”性质导致其在水界面处的浓度增加和空气-水界面的有效较低pH [Petersen等人，J. Phys. Chem. B 2004，108，14804]。
A new multistate empirical valence bond model (MS-EVB3) is developed for proton solvation and transport in aqueous solutions. The new model and its quantum version (qMS-EVB3) are based on the MS-EVB2 model [Day et al., J. Chem. Phys. 2002, 117, 5839] and recently developed flexible water models-the SPC/Fw model [Wu et al. J. Chem. Phys. 2006, 124, 24503] and the qSPC/Fw model [Paesani et al. J. Chem. Phys. 2006, 125, 184507]-for classical and quantum simulations, respectively. Using ab initio data as benchmarks, the binding energies and optimized geometries calculated with the new model for protonated water clusters, as well as the potential energy surface for proton shuttling between water molecules in a cluster environment, are improved in comparison to the MS-EVB2 model. For aqueous solutions, classical and quantum molecular dynamics simulations with the MS-EVB3 model yield a more accurate description of the solvation structure and diffusive dynamics of the excess proton. New insight is also provided into the proton solvation and hopping dynamics in water, as well as the "amphiphilic" nature of the hydrated proton that has been predicted to give rise to its enhanced concentration at aqueous interfaces and an effectively lower pH of the air-water interface [Petersen et al. J. Phys. Chem. B 2004, 108, 14804].