Vibrational spectrum at a water surface: a hybrid quantum mechanics/molecular mechanics molecular dynamics approach
Vibrational spectrum at a water surface: a hybrid quantum mechanics/molecular mechanics molecular dynamics approach
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水面振动谱：混合量子力学/分子力学分子动力学方法
DOI：
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发表时间：
2012
期刊：
影响因子：
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通讯作者：
A. Morita
中科院分区：
文献类型：
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作者：
T. Ishiyama;Hideaki Takahashi;A. Morita
首次将量子力学/分子力学（QM/MM）混合分子动力学（MD）模拟应用于汽/水界面表面取向结构和振动谱（二阶非线性磁化率）的计算。QM水分子的表面取向结构与前人的量子力学研究结果一致，计算得到的磁化率与实验结果一致，支持前人经典力场量子力学模拟的结果。本文的QM/MM MD模拟还表明，在氢键OH频率较低的区域，二阶非线性磁化率虚部的正号不是来自单个分子的取向结构，而是来自通过氢键网络的协同电子结构。
A hybrid quantum mechanics/molecular mechanics (QM/MM) molecular dynamics (MD) simulation is applied to the calculation of surface orientational structure and vibrational spectrum (second-order nonlinear susceptibility) at the vapor/water interface for the first time. The surface orientational structure of the QM water molecules is consistent with the previous MD studies, and the calculated susceptibility reproduces the experimentally reported one, supporting the previous results using the classical force field MD simulation. The present QM/MM MD simulation also demonstrates that the positive sign of the imaginary part of the second-order nonlinear susceptibility at the lower hydrogen bonding OH frequency region originates not from individual molecular orientational structure, but from cooperative electronic structure through the hydrogen bonding network.