Laser Spectroscopy of Ion and Clusters

在该项目中，加州大学伯克利分校的Saykally教授将继续他关于水和水簇性质的实验和理论研究项目，该项目由化学学部实验物理化学项目资助。利用太赫兹和红外腔衰荡光谱对水团簇的平移和振动-旋转-隧道（VRT）带进行了详细的研究。新的数据，包括平移和振动VRT波段，将用于生成改进的水二聚体电位表面。这些，反过来，将用于构建更大的水簇和液态水的电位，这将通过量子蒙特卡罗和分子动力学方法进行实验测试。类似的方法将用于质子化水簇的研究，使用太赫兹速度调制光谱和超音速放电等离子体。这里的目标是阐明质子转移动力学的细节，如质子隧道速率对分子间距离和取向的依赖。水是我们这个星球上最基本的物质，加强我们对其性质的理解将影响许多科学和技术领域。最近在地球大气中发现了水团，并预测对其化学有重要影响。研究生和本科生以及博士后研究助理将参与本研究。他们将因此获得当代物理化学前沿领域的宝贵经验。Saykally教授将继续积极参与一项推广计划，通过概述讲座、大众媒体和其他媒体，在有机会的时候，将科学的新发展带给广大公众。

In this project, funded by the Experimental Physical Chemistry Program of the Chemistry Division, Professor Saykally of the University of California at Berkeley will continue his experimental and theoretical research program on the properties of water and water clusters. Detailed studies of the translational and librational vibration-rotation-tunneling (VRT) bands of water clusters will be undertaken by means of terahertz and infrared cavity ring-down spectroscopies. The new data, which will include translational and librational VRT bands, will be used to generate improved water dimer potential surfaces. These, in turn, will be used to construct potentials for larger water clusters and liquid water, which will be tested against experiment with Quantum Monte Carlo and molecular dynamics methods. A similar approach will be used for the study of protonated water clusters, using terahertz velocity modulation spectroscopy and supersonic discharge plasmas. The goal here is to elucidate details of the proton transfer dynamics, such as the dependence of proton tunneling rates on intermolecular distances and orientation.Water is the most fundamental substance on our planet, and enhancing our understanding of its nature will impact many areas of science and technology. Water clusters have recently been detected in the earth's atmosphere, and are predicted to have important effects on its chemistry.Graduate and undergraduate students as well as postdoctoral research associates will participate in this research. They will thereby gain valuable experience in a forefront area of contemporary physical chemistry. Professor Saykally will continue to be active in an outreach program through overview lectures, the popular press, and other media, as opportunities arise, to bring new developments in science to the public at large.