AI 中文总结
该研究提出基于Hagedorn波包的从头算含时方法，通过构建重叠递推公式模拟多原子分子共振拉曼光谱，经二维模型验证后成功应用于蒽的66维势能面光谱计算。
AI 中文摘要
我们提出了一种实用的从头算含时方法，利用Hagedorn波包模拟多原子分子的共振拉曼（RR）光谱。Hagedorn函数是高斯函数乘以特定多项式，由于它们是至多二次势下含时薛定谔方程的精确解，且传播成本仅比引导高斯函数的传播略高，因此被用于表示RR初态和终态。通过使用高效递推公式计算Hagedorn波包之间的重叠，我们可以评估任意光谱信号的RR激发轮廓，如基频、泛音、组合带和热带。随后，我们从这些轮廓构建斯托克斯和反斯托克斯RR光谱。我们首先在二维位移、畸变且经Duschinsky旋转的谐波模型中，通过与数值精确的分裂算子计算对比验证该方法；接着将其应用于蒽的RR光谱计算，基于密度泛函理论计算构建的66维谐波势能面进行动力学模拟。
英文摘要
We present a practical, ab initio time-dependent method using Hagedorn wavepackets to simulate resonance Raman (RR) spectra of polyatomic molecules. Hagedorn functions---Gaussians multiplied by specific polynomials---are used to represent RR initial and final states because these functions are exact solutions to the time-dependent Schrödinger equation for at-most-quadratic potentials and can be propagated at zero cost beyond that of propagating the guiding Gaussian. Using efficient recursive formulae to compute overlaps between Hagedorn wavepackets, we can evaluate RR excitation profiles for arbitrary spectral signals, such as fundamental, overtone, combination, and hot bands. We then construct the Stokes and anti-Stokes RR spectra from these profiles. We first validate the method in a two-dimensional displaced, distorted, and Duschinsky-rotated harmonic model against numerically exact split-operator calculations. Then, we apply the method to compute RR spectra of anthracene by performing dynamics on a 66-dimensional harmonic potential energy surface constructed from density functional theory calculations.
