We describe a simplified approach to simulating Raman spectra from ab initio molecular dynamics (AIMD) calculations. The protocol relies on on-the-fly calculations of approximate molecular polarizabilities using the well-known sum over orbitals (as opposed to states) method. This approach bypasses the more accurate but computationally expensive approach to calculating molecular polarizabilities along AIMD trajectories, i.e., solving the coupled perturbed Hartree–Fock/Kohn–Sham equations. We demonstrate the advantages and limitations of our method through a few case studies targeting molecular systems of interest to surface- and/or tip-enhanced Raman spectroscopy practitioners.

中文翻译：

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EXPRESS：简化的基于 Ab Initio 分子动力学的拉曼光谱模拟

我们描述了一种从 ab initio 分子动力学 (AIMD) 计算模拟拉曼光谱的简化方法。该协议依赖于使用众所周知的轨道总和（而不是状态）方法对近似分子极化率的即时计算。这种方法绕过了计算沿 AIMD 轨迹的分子极化率的更准确但计算成本高的方法，即求解耦合扰动的 Hartree-Fock/Kohn-Sham 方程。我们通过针对表面和/或尖端增强拉曼光谱从业者感兴趣的分子系统的一些案例研究来证明我们方法的优点和局限性。