Advances in Coupled-Cluster Theory with Molecular Applications

约翰·斯坦顿是由理论和计算化学计划的支持，开发和应用量子化学方法的势能面和光谱的研究。 他的研究包括形式方法开发、计算实现和当前感兴趣的实验应用。 方法上的发展包括耦合簇理论的解析二阶导数，以及激发态和开壳层理论的梯度。 应用包括苯的泛频光谱、甲酸阴离子的光电子光谱和卡宾的电子激发态。精确的分子光谱模拟通常是研究分子性质和结构问题所必需的。例如，对大气和星际物质光化学的理论研究有助于通过光谱技术对其进行定性和检测。 然而，目前的计算方法往往是有限的，他们无法处理大分子和/或大区域的势能面。 本研究旨在解决这些缺陷。

John Stanton is supported by the Theoretical and Computational Chemistry Program to develop and apply quantum chemical methods to the study of potential energy surfaces and spectroscopy. His research contains a mix of formal method development, computational implementation, and applications of current interest to experiment. Methodological developments include analytic second derivatives for coupled cluster theory, as well as gradients for excited state and open-shell theories. Applications include the overtone spectroscopy of benzene, the photoelectron spectrum of the formic acid anion, and electronic excited states of carbenes.Accurate simulations of molecular spectroscopy are often necessary to investigate property and structural issues in molecules. For example, theoretical studies of the photochemistry of atmospheric and interstellar species assist in their characterization and detection by spectroscopic techniques. Current computational methodologies are often limited, however, by their inability to treat large molecules and/or large regions of potential energy surfaces. This research is intended to address these deficiencies.