Disentangling Many-Body Effects and Coupling in the Vibrational Spectra of Aqueous Clusters

在化学系化学结构、动力学和机理A项目的支持下，Francesco Paesani教授（加州大学圣地亚哥分校）和Ryan Steele教授（犹他大学）将合作研究带电粒子（称为离子）与水相互作用的方式。离子的水合作用驱动了许多过程，包括生物化学、大气化学和可再生能源化学。这些化学物质对红外光的反应为它们的行为提供了线索，但从实验中揭示这种行为的细节通常需要大规模的计算机模拟。这两个研究小组将使用新的计算机模拟，在原子水平上研究控制这些离子-水相互作用的过程。与此同时，研究人员将参与旨在向代表性不足群体的学生推广科学、技术、工程和数学（STEM）学科的外展和指导活动。特别是，Paesani教授将专注于整合加州大学圣地亚哥分校和圣地亚哥社区学院的学生在整个学年的研究项目。斯蒂尔教授将专注于通过犹他大学中学教师硕士项目指导高中化学教师，并将计算模拟整合到高中课程中。这两个研究小组将结合新开发的多体势能函数和新的局部模式方法来模拟非谐波振动光谱。这种协同作用将能够分解驱动强离子中独特振动行为的非谐波耦合，并为最近的水合离子实验提供见解。二价离子对氢键网络的影响也将被研究，以及小生物分子离子水化行为的演变。只要有可能，这些调查将与实验合作者最近和即将取得的结果相结合。最终，这些研究将用于校准势能函数及其潜在的物理性质，以模拟小的水合离子和冷凝相溶液。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

With support from the Chemical Structure, Dynamics, and Mechanism A program of the Division of Chemistry, Professors Francesco Paesani (University of California – San Diego) and Ryan Steele (The University of Utah) will collaboratively investigate the manner in which charged particles, called ions, interact with water. This hydration of ions drives numerous processes, including biological chemistry, atmospheric chemistry, and renewable-energy chemistry. The response of these chemical species to infrared light provides clues regarding their behavior, but unraveling the details of this behavior from experiments often requires large-scale computer simulations. The two research groups will use new computer simulations to study, at the atomic level, the processes that govern these ion-water interactions. In parallel, the investigators will be involved in outreach and mentoring activities designed to promote science, technology, engineering, and mathematics (STEM) disciplines among students from underrepresented groups. In particular, Professor Paesani will focus on integrating UC San Diego and San Diego community college students in research projects throughout the academic year. Professor Steele will focus on mentoring high-school chemistry teachers through M.S. Program for Secondary School Teachers at the University of Utah as well as in the integration of computational simulations into the high school curriculum.The two research groups will combine newly developed many-body potential energy functions with new local-mode approaches for simulating anharmonic vibrational spectroscopy. This synergy will enable the decomposition of the anharmonic couplings that drive unique vibrational behavior in strong ions and provide insight to recent hydrated-ion experiments. The impact of divalent ions on hydrogen-bonding networks will also be investigated, along with the evolution of hydration behavior of small biomolecular ions. Wherever possible, these investigations will be coupled with recent and forthcoming results from experimental collaborators. Ultimately, these studies will be used to calibrate the potential energy functions and their underlying physics, in order to simulate both small, hydrated ions and condensed-phase solutions.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.