Theory of Chemical Dynamics

加州大学伯克利分校的William米勒获得了化学理论、模型和计算方法项目的一项奖励，以开发新的、简单的和计算效率高的方法来研究电子非绝热化学过程。 当原子核的运动（例如分子振动）与电子的运动之间存在耦合时，就会发生这种过程。 它们涉及不同电子状态之间的跃迁，例如，基态（最低能量）和电子被激发的状态。 这些方法与许多重要的技术应用相关，这些技术应用与无机纳米材料和光合系统中的太阳能-电能转换以及“分子电子学”领域相关，例如，电子通过电极之间的各种分子结构的传输。 虽然非绝热过程本质上是量子力学的，但米勒和他的研究小组发现，它们可以通过对耦合动力学的简单而纯粹的经典处理来建模。 我们的目标是有一个方法，可以集成到现实系统的大规模模拟与许多自由度。PI为该领域的许多培训做出了广泛的贡献，这项工作的长期科学影响预计将是显着的。米勒和他的研究小组继续发展一种纯粹的经典方法来处理电子非绝热过程，建立在对称准经典过程（SQC）的基础上，SQC以等效的方式“量化”初始和最终的电子作用变量，从而确保微观可逆性。 该方法有其根源，在更早的迈耶-米勒（MM）和米勒-麦柯迪（MM）表示的电子自由度的经典作用角变量。 最近的应用程序给出了令人鼓舞的结果基准模型。 目前研究的目标是探索SQC/MM方法进一步发展的可能性。

William Miller of the University of California, Berkeley is supported by an award from the Chemical Theory, Models and Computational Methods program to develop new, simple and computationally efficient approaches to studying electronically nonadiabatic chemical processes. Such processes occur when there is a coupling between the motion of the atomic nuclei, for example molecular vibrations, and motion of the electrons. They involve transitions between different electronic states, for example, the ground (lowest energy) state and a state in which the electrons are excited. These processes have relevance for many important technological applications relevant to solar-to-electric energy conversion, in both inorganic nano-materials and in photosynthetic systems, and the field of "molecular electronics", e.g., the transmission of electrons through various molecular structures that are junctions between electrodes. Although nonadiabatic processes are inherently quantum mechanical, Miller and his group have found that they may be modeled by a simple and purely classical treatment of the coupled dynamics. The goal is to have an approach that can be integrated into large scale simulations of realistic systems with many degrees of freedom. The PI has contributed broadly to the training of many in the field and the long term scientific impact of this work is expected to be significant.Miller and his research group continue the development of a purely classical approach to treating electronically nonadiabatic processes, building on the symmetrical quasiclassical procedure (SQC) which "quantizes" both the initial and final electronic action variables in an equivalent fashion, thus insuring microscopic reversibility. The method has its roots in the much earlier Meyer-Miller (MM) and Miller-McCurdy (MM) representations of electronic degrees of freedom in terms of classical action-angle variables. Recent applications have given encouraging results for benchmark models. The goal of the current research is to explore a range of possibilities for further developments of the SQC/MM methods.