Theoretical Studies of Water Clusters with Excess Protons and Electrons and of Biomolecule Energy Landscapes

肯尼斯·D匹兹堡大学的乔丹得到了理论和计算化学计划的一个奖项的支持，继续他的研究，以了解质子缺陷的定位与质子化水簇和过量电子水簇系统振动光谱中的强非谐效应之间的联系。正在开发用于探索势能面和对质子化水簇进行模拟的改进模型。在上一个奖项期间开发的用于处理过量电子与极性分子团簇相互作用的Drude模型正在修改，以允许其用于模拟包含20个或更多水分子的团簇，并将与更复杂的水模型相结合。第三个研究重点涉及绘制小的、构象灵活的生物分子的势能面，这些生物分子既可以是孤立的，也可以是与一个或多个水分子溶剂化的。本研究的目标是在足够高的理论水平上为选定的系统表征所有低能量途径，以明确地建立实验访问的途径，并为测试和改进可极化力场提供数据，以便随后用于表征更复杂的生物分子。在更广泛的影响方面，PI在吸引本科生参与研究以及将本科生和研究生引入计算科学领域方面有着良好的记录，包括指导本科生为期四年的暑期研究计划，并建立匹兹堡大学的分子和材料模拟中心。

Kenneth D. Jordan of the University of Pittsburgh is supported by an award from the Theoretical and Computational Chemistry program to continue his research on understanding the connection between localization of the proton defect and strong anharmonic effects in the vibrational spectra of protonated water clusters and excess electron-water cluster systems. Improved models for exploring the potential energy surfaces and for carrying out simulations on protonated water clusters are being developed. The Drude-model for treating the interaction of an excess electron with clusters of polar molecules that was developed during the previous award is being modified to permit its use in simulations of clusters containing twenty or more water molecules and will be combined with more sophisticated water models. A third research thrust involves mapping out the potential energy surfaces of small, conformationally flexible biomolecules, both isolated and solvated with one or more water molecules. The goals of this research are to characterize for selected systems all low-energy pathways at a sufficiently high level of theory to unambiguously establish the pathways accessed experimentally, and to provide data for testing and refining the polarizable force fields for subsequent use in characterizing more complex biomolecules. In terms of broader impacts, the PI has a strong track record of engaging undergraduates in research and in introducing undergraduate and graduate students to the field of computational science, including directing summer research programs for undergraduates for four years and establishing the University of Pittsburgh's Center for Molecular and Materials simulations.