Bottlenecks to vibrational energy flow in OCS: Structures and mechanisms

Quantum dynamics of the intramolecular vibrational energy redistribution in OCS: From localization to quasi-thermalization

We report a fully quantum-dynamical study of the intramolecular vibrational energy redistribution (IVR) in the electronic ground state of carbonyl sulfide (OCS), which is a prototype of an isolated many-body quantum system with strong internal couplings and non-Rice-Ramsperger-Kassel-Marcus (RRKM) behavior. We pay particular attention to the role of many-body localization and the approach to thermalization, which currently are topics of considerable interest, as they pertain to the very foundations of statistical mechanics and thermodynamics. We employ local-mode (valence) coordinates and cons…

Sticky obstacles to intramolecular energy flow

Vibrational energy flows unevenly in molecules, repeatedly going back and forth between trapping and roaming. We identify bottlenecks between diffusive and chaotic behavior, and describe generic mechanisms of these transitions, taking the carbonyl sulphide molecule OCS as a case study. The bottlenecks are found to be lower-dimensional tori; their bifurcations and unstable manifolds govern the transition mechanisms.

观测从分子形状共振到振电Feshbach共振的共振隧穿及随后的模式特异性碎裂

Observation of Resonant Tunneling from Molecular Shape into Vibronic Feshbach Resonances Followed by Mode-Specific Fragmentation

本研究通过实验和EA-EOMCCSD理论计算，揭示了线性OCS分子在DEA过程中由分子形状共振向振电Feshbach共振的非绝热隧穿机制，阐明了模式特异性碎裂的动力学途径。

基于拉格朗日介数的Li-NC ↔ Li-CN异构化反应中的过渡态与动力学瓶颈

Transition states and dynamical bottlenecks in the Li-NC <-> Li-CN isomerizing reaction with the Lagrangian betweenness

该研究用拉格朗日介数识别Li-NC ↔ Li-CN异构化反应的过渡态与动力学瓶颈，为分析化学反应的振动动力学提供了新方法。

On the benefits of localized modes in anharmonic vibrational calculations for small molecules

Anharmonic vibrational calculations can already be computationally demanding for relatively small molecules. The main bottlenecks lie in the construction of the potential energy surface and in the size of the excitation space in the vibrational configuration interaction (VCI) calculations. To address these challanges, we use localized-mode coordinates to construct potential energy surfaces and perform vibrational self-consistent field (L-VSCF) and L-VCI calculations [P. T. Panek, Ch. R. Jacob, ChemPhysChem 15, 3365 (2014)] for all vibrational modes of two prototypical test cases, the ethene an…

使用谐振子或VSCF模的半随机微扰理论振动热浴组态相互作用方法

Vibrational heat-bath configuration interaction with semistochastic perturbation theory using harmonic oscillator or VSCF modals

本研究针对振动热浴组态相互作用（VHCI）方法，用半随机方法解决其二阶微扰校正的内存瓶颈，还提出新热浴判据与隐式排序算法，并对比了VSCF与谐振子参考的VHCI表现。