Ibele Lea M, Curchod Basile F E
Department of Chemistry, Durham University, South Road, Durham DH1 3LE, UK.
Phys Chem Chem Phys. 2020 Jul 21;22(27):15183-15196. doi: 10.1039/d0cp01353f. Epub 2020 Jun 25.
Over the past decades, an important number of methods have been developed to simulate the nonadiabatic dynamics of molecules, that is, the dynamics of molecules beyond the Born-Oppenheimer approximation. These nonadiabatic methods differ in the way they approximate the dynamics emanating from the time-dependent molecular Schrödinger equation. In 1990, Tully devised a series of three one-dimensional model systems to test the approximations of the method called trajectory surface hopping. The Tully models were designed to probe different scenarios of nonadiabatic processes, such as single and multiple nonadiabatic (re)crossings. These one-dimensional models rapidly became the testbed for any new nonadiabatic dynamics strategy. In this work, we present a molecular perspective to the Tully models by highlighting a correspondence between these simple one-dimensional models and processes happening during the excited-state dynamics of molecules. More importantly, each of these nonadiabatic processes can be connected to a given exemplary molecular system, and we propose here three molecules that could serve as molecular Tully models, reproducing some of the key features of the original models but this time in a high-dimensional space. We compare trajectory surface hopping with the ab initio multiple spawning for the three molecular Tully models and highlight particular features and differences between these methods resulting from their distinct approximations. We also provide all the necessary information - initial conditions and all required parameters for the dynamics as well as the electronic structure - employed in our simulations such that the molecular Tully models can become in the future a unified and standardized test for ab initio nonadiabatic molecular dynamics methods. The molecular Tully models also offer an exciting link between the world of low-dimensional model systems for nonadiabatic dynamics and the excited-state dynamics of molecular systems in their full dimensionality.
在过去几十年里，人们开发了大量方法来模拟分子的非绝热动力学，即超越玻恩 - 奥本海默近似的分子动力学。这些非绝热方法在近似含时分子薛定谔方程所产生的动力学的方式上有所不同。1990年，塔利设计了一系列三个一维模型系统，以测试所谓的轨迹表面跳跃方法的近似情况。塔利模型旨在探究非绝热过程的不同情形，比如单次和多次非绝热（再）交叉。这些一维模型迅速成为任何新的非绝热动力学策略的试验台。在这项工作中，我们通过强调这些简单的一维模型与分子激发态动力学过程之间的对应关系，从分子角度审视塔利模型。更重要的是，这些非绝热过程中的每一个都可以与一个给定的典型分子系统相关联，我们在此提出三种分子，它们可作为分子塔利模型，再现原始模型的一些关键特征，但这一次是在高维空间中。我们针对这三种分子塔利模型，将轨迹表面跳跃与从头算多重产生方法进行比较，并突出这些方法因其不同近似而产生的特定特征和差异。我们还提供了模拟中使用的所有必要信息——动力学的初始条件和所有所需参数以及电子结构——以便分子塔利模型未来能够成为对从头算非绝热分子动力学方法的统一和标准化测试。分子塔利模型还在非绝热动力学的低维模型系统世界与全维分子系统的激发态动力学之间提供了一个令人兴奋的联系。
