An improvement in quantum mechanical description of solute-solvent interactions in condensed systems via the number-adaptive multiscale quantum mechanical/molecular mechanical-molecular dynamics method: application to zwitterionic glycine in aqueous solution.
An improvement in quantum mechanical description of solute-solvent interactions in condensed systems via the number-adaptive multiscale quantum mechanical/molecular mechanical-molecular dynamics method: application to zwitterionic glycine in aqueous solution.
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DOI：
10.1063/1.4732307
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发表时间：
2012-07
期刊：
影响因子：
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通讯作者：
N. Takenaka;Y. Kitamura;Yoshiyuki Koyano;M. Nagaoka
中科院分区：
文献类型：
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作者：
N. Takenaka;Y. Kitamura;Yoshiyuki Koyano;M. Nagaoka
在量子力学/分子力学（QM/MM）框架内，提出了一种有效的方法来改进凝聚态体系中溶质-溶剂相互作用的QM描述。它是基于最近发展的自适应多尺度QM/MM- md方法的新处理，即数字自适应多尺度方法，它将溶质周围的紧密溶剂分子纳入QM区域，并使它们能够在QM和MM区域之间的边界上流动。我们将其应用于两性离子（ZW）甘氨酸分子的水溶液中，研究了其水化结构和电荷分布，并与仅对溶质甘氨酸分子进行量子力学处理的标准（SD）方法进行了比较。结果表明，总能量和温度守恒良好，为ZW甘氨酸分子在水溶液中的水化数和诱导极化提供了合理的条件。而SD法由于电子分布表达不当，与实验方法相比，高估了水化数。总之，本方法作为研究凝聚态体系中各种化学现象的定量统计抽样方法是非常有用的。
An efficient methodology is presented to improve the QM description of solute-solvent interactions in condensed systems within the quantum mechanical/molecular mechanical (QM/MM) framework. It is based on the recently developed new treatment of the adaptive multiscale QM/MM-MD method, i.e., the number-adaptive multiscale method that includes the close solvent molecules around the solute into QM region and enables them to flow across the boundary between the QM and MM regions. We have applied it to zwitterionic (ZW) glycine molecule in aqueous solution, and investigated the hydration structures and charge distributions, which are compared with those by the standard (SD) method that only a solute glycine molecule is treated quantum mechanically. It is shown that the total energy and temperature are satisfactorily conserved, providing reasonable hydration numbers and induced polarization of ZW glycine molecule in aqueous solution. In contrast, the SD method is found overestimated the hydration numbers in comparison to the experimental ones due to the inappropriate expression of the electron distribution. In conclusion, the present method should become quite useful as the quantitative statistical sampling method to study various chemical phenomena in condensed systems.