Department of Chemistry, Graduate School of Science, Kyoto University, Kyoto 606-8502, Japan.
J Chem Phys. 2023 Jan 28;158(4):044115. doi: 10.1063/5.0135725.
A model of a bulk water system describing the vibrational motion of intramolecular and intermolecular modes is constructed, enabling analysis of its linear and nonlinear vibrational spectra as well as the energy transfer processes between the vibrational modes. The model is described as a system of four interacting anharmonic oscillators nonlinearly coupled to their respective heat baths. To perform a rigorous numerical investigation of the non-Markovian and nonperturbative quantum dissipative dynamics of the model, we derive discretized hierarchical equations of motion in mixed Liouville-Wigner space, with Lagrange-Hermite mesh discretization being employed in the Liouville space of the intramolecular modes and Lagrange-Hermite mesh discretization and Hermite discretization in the Wigner space of the intermolecular modes. One-dimensional infrared and Raman spectra and two-dimensional terahertz-infrared-visible and infrared-infrared-Raman spectra are computed as demonstrations of the quantum dissipative description provided by our model.
构建了一个描述分子内和分子间振动模式振动运动的体相体系模型，使我们能够分析其线性和非线性振动光谱以及振动模式之间的能量转移过程。该模型被描述为一个由四个相互作用的非线性耦合到各自热浴的非简谐振荡器组成的系统。为了对模型的非马尔可夫和非微扰量子耗散动力学进行严格的数值研究，我们在混合刘维尔-维格纳空间中推导出离散的层次运动方程，其中在分子内模式的刘维尔空间中采用拉格朗日-赫尔米特网格离散化，在分子间模式的维格纳空间中采用拉格朗日-赫尔米特网格离散化和赫尔米特离散化。作为我们模型提供的量子耗散描述的演示，计算了一维红外和拉曼光谱以及二维太赫兹-红外-可见和红外-红外-拉曼光谱。
