具有杜申斯基（Duschinsky）耦合和有限温度的高阶响应函数：在二维共振拉曼光谱中的应用
High-Order Response Functions with Duschinsky Coupling and Finite Temperature: Application to Two-Dimensional Resonance Raman Spectroscopy
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中文总结 AI 辅助
该研究推导了含杜申斯基耦合与有限温度的高阶光谱响应函数闭式表达式，应用其计算五阶二维共振拉曼光谱，证实该光谱可作为分子体系杜申斯基耦合的独特特征。
中文摘要 AI 辅助
在本工作中，我们在简谐近似框架下推导了高阶非线性光谱响应函数所依赖的多时间关联函数的闭式表达式。该方法涵盖了不同电子态振动模式之间的位移、频率变化以及杜申斯基（Duschinsky）旋转，同时保持了与自由度数量成多项式比例的计算规模。我们无需对振动本征态求和即可计入有限温度效应。为展示该方法的能力，我们将其应用于计算双模模型体系及萘的五阶二维共振拉曼（2DRR）光谱。与位移简谐振子模型的对比表明，杜申斯基（Duschinsky）旋转会改变对角峰和交叉峰的位置及相对强度。总体而言，我们的结果证实，二维共振拉曼（2DRR）光谱对电子态之间简正坐标的变化极为敏感，可作为分子体系中杜申斯基（Duschinsky）耦合的独特特征。
英文摘要
In this work, we derive closed-form expressions for multi-time correlation functions underlying higher-order nonlinear spectroscopic response functions within the harmonic approximation. Our method includes displacements, frequency changes, and Duschinsky rotation between the vibrational modes of different electronic states while retaining polynomial scaling with the number of degrees of freedom. Finite temperature is accounted for without summation over vibrational eigenstates. To show the capabilities of our method, we apply it to calculate fifth-order two-dimensional resonance Raman (2DRR) spectra of two-mode model systems and naphthalene. Comparison with the displaced harmonic oscillator model shows that Duschinsky rotation modifies the positions and relative intensities of diagonal and cross peaks. Overall, our results demonstrate that 2DRR spectroscopy is particularly sensitive to changes in normal coordinates between electronic states and can provide distinct signatures of Duschinsky coupling in molecular systems.
