CDS&E: Bridging electronic structure theory and dynamics with applications to nonadiabatic processes

密苏里科技大学的理查德·道斯（Richard Dawes）因其在创造高精度势能面（PES）方法方面的工作而获得了化学理论、模型和计算方法项目的奖项。该奖项由高级网络基础设施部门的计算和数据支持科学与工程项目共同资助。PES是化学家思考分子系统结构和动力学的核心，即通过穿越景观或越过能量障碍的路径连接的极小值和渐近线。道斯和他的同事创造的势能面用于研究分子动力学和光谱数据，这些数据与许多化学过程有关，包括大气化学、天体化学和燃烧。该项目的一个主要推力是开发一个用户友好的、自由分发的软件包，以支持和使更广泛的社区成员，包括实验家和理论家，创建他们自己的势能面来研究各种不同的系统。该项目的目标是开发用户友好的软件，作为执行电子结构计算的代码和计算感兴趣的动态的代码之间的桥梁。其思想是用如此高的保真度来表示电子结构数据，使计算的动力学直接反映电子结构计算的底层水平。（这种契合只能使动态代码所需的数百万次潜在评估变得负担得起）。为了评估细微不同方法的性能或小校正项的重要性，需要非常高的拟合精度。Dawes教授之前的工作已经产生了相当精确的插值方法，称为插值移动最小二乘（IMLS）。所开发的自动化拟合方法减少了PES生成的瓶颈，并产生了大量光谱精确的PES。目前的计划是开发一个通用的、可扩展的软件发行版，社区中的其他人可以使用它来生成和适应他们自己的PES。这个项目的特别重点是涉及几个耦合pe的过程。这涉及到系统的研究，其中包括各种电子状态之间的非绝热相互作用，如锥形交叉，雷纳-泰勒相互作用，和自旋轨道耦合。在实际应用中对这些效应的精确处理代表了理论动力学的前沿。

Richard Dawes of the Missouri University of Science and Technology is supported by an award from the Chemical Theory, Models and Computational Methods program for his work on methods that create highly accurate potential energy surfaces (PES). This award is cofunded by the Computational and Data-Enabled Science and Engineering program in the Division of Advanced Cyberinfrastructure. The PES are central to how chemists think about the structure and dynamics of molecular systems, in terms of minima and asymptotes connected by paths across landscapes or over energetic barriers. The potential energy surfaces that Dawes and his coworkers create are used to study molecular dynamics and spectroscopy data that is relevant to many chemical processes including atmospheric chemistry, astrochemistry, and combustion. A major thrust of the project is to develop a user-friendly, freely-distributed software package to support and enable members of a wider community, both experimentalists and theorists, to create their own potential energy surfaces to study a large variety of different systems. The goal of this project is to develop user-friendly software that acts as a bridge between codes that perform electronic structure calculations and those that compute the dynamics of interest. The idea is to represent the electronic structure data with such high-fidelity that the computed dynamics directly reflect the underlying level of electronic structure calculations. (The fit only serves to render affordable the millions of potential evaluations required by dynamics codes). Very high fitting accuracy is required in order to assess the performance of subtly different methods or the importance of small correction terms. Previous work by Professor Dawes has resulted in suitably accurate interpolative methods known as interpolating moving least squares (IMLS). The automated fitting methods that were developed have reduced the bottleneck of PES generation and produced a stockpile of spectroscopically accurate PES. The current plan is to develop a generalized, extendable software distribution that others in the community can use to generate and fit their own PES. The particular focus of this project is on processes involving several coupled PES. This involves systematic studies of systems which include various non-adiabatic interactions between electronic states such as conical intersections, Renner-Teller interactions, and spin-orbit coupling. Accurate treatment of these effects in real applications represents the frontier of theoretical dynamics.