Theoretical studies of spectroscopic and dynamic implications of large amplitude vibrations

俄亥俄州立大学的Anne McCoy获得了化学系化学理论、模型和计算方法项目的奖励，以开发理论工具来揭示经历大振幅运动的分子系统的光谱和动力学。这项工作涉及扩散蒙特卡罗（DMC）技术的扩展，包括“动态”DMC的发展，以及使用DMC来评估可测量的量，包括反振动跃迁的能量和强度。McCoy和她的同事正在使用扩散蒙特卡罗来开发势能和偶极矩表面。他们还采用降维方法来探索光诱导质子易位和更普遍的氢键的光谱表现。该研究的重点是实验学家和理论家当前感兴趣的系统，其结果将用于从光谱测量中提取物理见解。通过开辟广泛的分子和离子系统的研究，除了加深我们对水溶液中氢键和质子转移的理解外，这项工作还对天体化学和环境重要性系统的研究产生了广泛的影响。参与这项研究的大多数学生来自物理科学领域代表性不足的群体。

Anne McCoy of The Ohio State University is supported by an award from the Chemical Theory, Models and Computational Methods program within the Division of Chemistry for the development of theoretical tools to unravel the spectroscopy and dynamics of molecular systems that undergo large amplitude motions. The work involves extensions of the Diffusion Monte Carlo (DMC) technique including the development of "on-the-fly" DMC and using DMC to evaluate measurable quantities including energies and intensities of ro-vibrational transitions. McCoy and her coworkers are using Diffusion Monte Carlo to develop potential energy and dipole moment surfaces. They also employ reduced dimensional approaches to explore photoinduced proton translocation and spectroscopic manifestations of hydrogen bonding more generally. The research focuses on systems of current interest to experimentalists as well as theorists, and the results will be used to extract physical insights from spectroscopic measurements.By opening up a broad range of molecular and ionic systems for investigation, the work is having a broad impact on the study of systems of astrochemical and environmental importance in addition to deepening our understanding of hydrogen bonding and proton transfer in aqueous solution. The majority of students engaged in this research are from under-represented groups in the physical sciences.