Department of Chemistry, Graduate School of Science, Kyoto University, Kyoto 606-8502, Japan.
J Phys Chem B. 2011 May 12;115(18):5545-53. doi: 10.1021/jp111308f. Epub 2011 Apr 12.
We have developed a polarizable water model for classical molecular dynamics simulations of vibrational spectroscopies, which covers from low-frequency intermolecular modes to high-frequency intramolecular vibrational modes. The model utilizes the ab initio derived geometry-dependent multipole moment surfaces to depict the instantaneous charge density of a water molecule. Multipoles up to quadrupole are included for the permanent multipoles, while those up to dipole are included for the induced multipoles. The polarization of molecules is described by a distributed polarizability model. At room temperature, the present model is able to reproduce experimental infrared and Raman spectra of intramolecular vibrational modes, except for the blue peak shift due to a limitation of the classical simulation based on a quantum mechanical potential. The calculated infrared spectrum for low-frequency intermolecular modes agreed reasonably well with the experimental signals.
我们开发了一种可极化的水分子模型，用于经典分子动力学模拟振动光谱，涵盖了从低频分子间模式到高频分子内振动模式。该模型利用从头算得到的与几何相关的多极矩面来描述水分子的瞬时电荷密度。永久多极矩包含四极矩，而诱导多极矩包含偶极矩。分子的极化用分布式极化率模型来描述。在室温下，本模型能够重现实验得到的分子内振动模式的红外和拉曼光谱，除了由于基于量子力学势的经典模拟的限制导致的蓝移峰。低频分子间模式的计算得到的红外光谱与实验信号相当吻合。
