Advances in Coupled-Cluster Theory with Molecular Applications

德克萨斯大学的约翰·斯坦顿（John Stanton）得到了理论与计算化学项目的支持，开发和应用新的理论方法来处理自由基和双自由基。这些方法基于耦合簇理论，强调高度精确的处理，并且应用于瞬态分子物种，这需要平衡描述几种电子构型。此外，还将建立涉及非绝热振动耦合效应的电子能谱处理模型，并对激发态势能面上的振动能级进行精确计算。自由基在化学的许多领域发挥着核心作用，包括有机化学、燃烧过程、大气和星际化学。在这个研究项目中开发的新技术将允许对这些物种的特性进行极其准确和可靠的预测。将开发易于使用的计算机程序，将这些新技术结合起来，并允许将来将其常规应用于相关问题。

John Stanton of the University of Texas is supported by the Theoretical and Computational Chemistry Program to develop and apply new theoretical methods for the treatment of radicals and biradicals. The methods are based on coupled-cluster theory, which emphasizes highly accurate treatments, and the applications are transient molecular species, which require a balanced description of several electronic configurations. In addition, models for the treatment of electronic spectra that involve nonadiabatic vibronic coupling effects will be developed, and accurate calculations of vibrational levels on excited state potential energy surfaces will be performed.Radical species play a central role in many areas of chemistry, included organic chemistry, combustion processes, and atmospheric and interstellar chemistry. The new techniques developed in this research project will allow extremely accurate and reliable predictions of the properties of these species. Easy-to-use computer programs will be developed that incorporate these new techniques and that allow for future, routine application to related problems.