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arXiv physics/0310158physics.chem-phphysics.bio-ph
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基于准化学理论和从头算分子动力学的K+(aq)内壳层定义和绝对水合自由能

Inner Shell Definition and Absolute Hydration Free Energy of K+(aq) on the Basis of Quasi-chemical Theory and Ab Initio Molecular Dynamics

Susan B. Rempe, D. Asthagiri, Lawrence R. Pratt

摘要:

K+(aq)离子是许多细胞过程的组成部分,其中最重要的可能是其在沿神经传递电脉冲中的作用。了解其水化结构和热力学是至关重要的解剖它在这些过程中的作用。在这里,我们解决这些问题,同时使用统计力学准化学理论的解决方案和从头算分子动力学模拟。模拟预测了K+(aq)的有趣的水合结构:在无限稀释下观察到的g_{KO}(r)的初始最小值内约6个水分子的群体涉及准化学理论建议应被视为理论内壳的4个最内部分子。第5和第6个最接近的水分子的贡献可以观察到,作为g_{KO}(r)的主极大值上的明显肩部。中性对KOH的溶剂化自由能的准化学估计也与实验符合得很好。

英文摘要:

K+(aq) ion is an integral component of many cellular processes, amongst which the most important, perhaps, is its role in transmitting electrical impulses along the nerve. Understanding its hydration structure and thermodynamics is crucial in dissecting its role in such processes. Her we address these questions using both the statistical mechanical quasi-chemical theory of solutions and ab initio molecular dynamics simulations. Simulations predict an interesting hydration structure for K+(aq): the population of about six (6) water molecules within the initial minimum of the observed g_{KO}(r) at infinite dilution involves four (4) inner-most molecules that the quasi-chemical theory suggests should be taken as the theoretical inner shell. The contribution of the 5th and 6th closest water molecules is observable as a distinct shoulder on the principal maximum of the g_{KO}(r). The quasi-chemical estimate of solvation free energy for the neutral pair KOH is also in good agreement with experiments.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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