Advances in Coupled-Cluster Theory with Molecular Applications

德克萨斯大学奥斯汀分校的约翰·斯坦顿（John Stanton）获得了化学学部理论、模型和计算方法项目的奖励，以开发针对特定应用的基于耦合簇理论的新的计算和理论方法。该奖项由保险业监理处的一项试点计划共同资助，该计划旨在促进网络基础设施（CI）元素的再利用。斯坦顿小组正在开发处理自由基和双基的方法，开发相互作用系统的（准）非绝热表示，改进其他高精度耦合簇技术的实现，并扩展他们描述强相互作用系统光谱的能力，以包括低阶多项式表示势的分子。应用范围包括硝酸盐自由基、自由基和瞬态中间体的高分辨率电子和光电子谱等光谱问题。另一个应用是一个旨在确定原型生物质分子热降解的分子机制的项目。大部分应用工作是与美国领先的实验小组合作完成的。Stanton小组完成的理论方法开发最终包含在免费分发的计算包cfour1中。斯坦顿小组开发的用于分析分子光谱的工具针对的是广泛的研究人员群体，特别是那些不是计算化学专家的实验人员。该计划资助的研究正在将这些代码的有用性扩展到更广泛的科学家群体。本科生对这个研究项目非常投入。

John Stanton of the University of Texas Austin is supported by an award from the Theory, Models and Computational Methods program in the Chemistry division to develop new computational and theoretical approaches based on coupled-cluster theory that are aimed at specific applications. The award is co-funded by a pilot program in OCI promoting the reuse of Cyberinfrastructure (CI) elements. The Stanton group is developing methods to treat radicals and biradicals, developing (quasi)diabatic representations for interacting systems, improving the implementation of other high-accuracy coupled-cluster techniques and extending their ability to describe the spectra of strongly interacting systems to include molecules for which a low-order polynomial representation of the potential is inadequate. Applications include spectroscopically interesting problems such as the nitrate radical and high-resolution electronic and photoelectron spectra of radicals and transient intermediates. An additional application is a project aimed at determining molecular mechanisms of thermal degradation of prototype biomass molecules. Much of the application work is done in collaboration with leading experimental groups in the United States. The theoretical method development performed by the Stanton group is ultimately included in the computational package cfour1 which is distributed free of charge. The tools that the Stanton group develops for analyzing molecular spectra are aimed at a broad group of researchers, particularly experimentalists who are not experts in computational chemistry. The research funded under this program is extending the usefulness of these codes to a wider group of scientists. Undergraduates are very involved in this research program.