以瞬間正則模分析水的拉曼光譜：延伸偶極感應交互作用

Abstract

利用MD simulation模擬水分子在液體中的運動，在相隔一定的時間間距內，取得水分子分佈組態。從這些組態中，我們可以得到各個時間點的collective polarizability。當電磁波打入液體水時，隨時變的collective polarizability會使入射電磁波散射，產生拉曼光譜。此篇論文主要是利用instantaneous normal mode (簡稱INM)的方法來分析rigid water的拉曼光譜。在其他的論文中是用time correlation function(TCF)來分析水的拉曼光譜，而本論文的目的是要和他們的結果做比較，並進一步地對水的local structure作分類，探討其拉曼光譜的差異。

By using the MD simulation to simulate the motion of molecules in water. In the same time interval, we collect the configurations of water. From these configurations, we obtain collective polarizability at different instants. When the incident electro- magnetic waves penetrate into liquid water, time dependent collective polarizability causes electromagnetic waves to scatter, and the Raman spectrum is observed. In this project, we use the instantaneous normal modes to analyze the Raman spectrum of water. In other paper , the time correlation fuction(TCF) was used to analyze the spectrum. Our purpose is to compare our results with theirs. Also, by classifying the local structure of water molecules, we discuss the difference of Raman spectrum due to different local structures.