Mandal Souvik, Gatti Fabien, Bindech Oussama, Marquardt Roberto, Tremblay Jean Christophe
Laboratoire de Physique et Chimie Théoriques, UMR 7019 CNRS/Université de Lorraine, 1 Blvd. Arago, 57070 Metz, France.
Institut de Sciences Moléculaires d'Orsay, UMR 8214 CNRS/Université Paris-Saclay, Bât 520, Rue André Rivière, 91405 Orsay Cedex, France.
J Chem Phys. 2022 Oct 14;157(14):144105. doi: 10.1063/5.0105308.
In this article, we explore the dissipation dynamics of a strongly coupled multidimensional system in contact with a Markovian bath, following a system-bath approach. We use in this endeavor the recently developed stochastic multi-configuration time-dependent Hartree approach within the Monte Carlo wave packet formalism [S. Mandal et al., J. Chem. Phys. 156, 094109 (2022)]. The method proved to yield thermalized ensembles of wave packets when intramolecular coupling is weak. To treat strongly coupled systems, new Lindblad dissipative operators are constructed as linear combinations of the system coordinates and associated momenta. These are obtained by a unitary transformation to a normal mode representation, which reduces intermode coupling up to second order. Additionally, we use combinations of generalized raising/lowering operators to enforce the Boltzmann distribution in the dissipation operators, which yield perfect thermalization in the harmonic limit. The two ansatz are tested using a model two-dimensional Hamiltonian, parameterized to disentangle the effects of intramolecular potential coupling, of strong mode mixing observed in Fermi resonances, and of anharmonicity.
在本文中，我们采用系统 - 浴方法探究与马尔可夫浴接触的强耦合多维系统的耗散动力学。在此过程中，我们运用了蒙特卡罗波包形式体系中最近发展的随机多组态含时哈特里方法[S. 曼达尔等人，《化学物理杂志》156, 094109 (2022)]。当分子内耦合较弱时，该方法被证明能产生热化的波包系综。为了处理强耦合系统，新的林德布拉德耗散算符被构造为系统坐标和相关动量的线性组合。这些是通过对正则模表示进行幺正变换得到的，这将模间耦合降低到二阶。此外，我们使用广义升降算符的组合来在耗散算符中强制实现玻尔兹曼分布，这在谐振极限下能实现完美热化。使用一个二维哈密顿量模型对这两种假设进行了测试，该模型经过参数化处理以区分分子内势耦合、费米共振中观察到的强模混合以及非谐性的影响。
