Theoretical Studies of Spectral Signatures of Large Amplitude Vibrational Motions

大振幅振动运动谱特征的理论研究

• 批准号: 1619660
• 负责人: Anne McCoy
• 金额: $ 61.5万
• 依托单位: University of Washington
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-12-01 至 2019-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1619660&HistoricalAwards=false
• 关键词: Theoretical; Studies; Spectral; Signatures; Large

Anne McCoy of Ohio State University is supported by an award from the Chemical Theory, Models and Computational Methods program in the Chemistry division to develop theoretical and computational tools needed to understand the spectra of molecules in which the atoms in the molecules undergo large amplitude motions. The work has a particular focus on protonated and hydrogen bonded systems. This class of molecules can be found close to home in our atmosphere and also far away in the interstellar medium. Such molecular systems also provide prototypes to understand the solvation of ions in water. Experimentalists use vibrational spectroscopy to study these molecules. In the case of astrochemistry, vibrational spectroscopy provides the best method for studying chemical composition. Unlike many common molecules, however, the bonding in these systems is weak. Most of the models that have been developed to predict and interpreted rotation/vibration spectroscopy do not apply to them. By developing these new approaches, McCoy and her research group are addressing this deficiency. The results of these studies will be used to develop connections between spectra and structure and bonding. McCoy and her research group collaborate with experimental research groups on all of these projects. This research program provides educational and research opportunities for both undergraduates and graduate students. McCoy is very active in encouraging women and other members of under-represented groups to pursue careers in science. Of particular interest is the interaction between rotation and vibration motions. To this end, the McCoy group is developing several Monte Carlo-based techniques to probe these interactions. Much of the proposed work involves the Diffusion Monte Carlo approach, with an emphasis on extending the range of properties that can be calculated using this general approach. In addition, they employ an approach based on Monte Carlo sampling of potential surfaces to deepen the understanding of the origins of the broadening of spectral features in hydrogen bonded systems. Specific applications include molecules, specifically H5+ and CH5+ that are of astrochemical interest, as well as several studies that probe the origins of spectral signatures of hydrogen bonding.

俄亥俄州立大学的Anne McCoy获得了化学学部化学理论、模型和计算方法项目的奖励，她开发了理解分子光谱所需的理论和计算工具，其中分子中的原子经历了大幅运动。这项工作特别关注质子化和氢键系统。这类分子可以在离地球很近的大气中找到，也可以在遥远的星际介质中找到。这样的分子系统也为理解离子在水中的溶剂化提供了原型。实验学家使用振动光谱学来研究这些分子。就天体化学而言，振动光谱学为研究化学成分提供了最好的方法。然而，与许多普通分子不同，这些系统中的键合很弱。大多数已经开发的预测和解释旋转/振动光谱的模型并不适用于它们。通过开发这些新方法，McCoy和她的研究小组正在解决这一缺陷。这些研究的结果将用于发展光谱与结构和键合之间的联系。McCoy和她的研究小组在所有这些项目上都与实验研究小组合作。该研究项目为本科生和研究生提供教育和研究机会。麦考伊非常积极地鼓励女性和其他代表性不足的群体成员从事科学事业。特别令人感兴趣的是旋转和振动运动之间的相互作用。为此，McCoy小组正在开发几种基于蒙特卡罗的技术来探测这些相互作用。许多提议的工作涉及扩散蒙特卡罗方法，重点是扩展可以使用这种通用方法计算的属性范围。此外，他们采用了一种基于蒙特卡罗电位表面采样的方法来加深对氢键系统中光谱特征拓宽的起源的理解。具体的应用包括分子，特别是与天体化学相关的H5+和CH5+，以及一些探索氢键光谱特征起源的研究。