Hydrogen molecules in nanoscale confinement: A combined eigenstate-resolved/path integral study of the quantum translation-rotation dynamics, spectroscopy, and diffusion

纽约大学的Zlatko Bacic(Pi)和Mark E.Tuckerman(co-Pi)获得了化学部化学结构、动力学和机制项目的奖励，这是一项计算研究，旨在实现对不同主体材料(如笼状水合物、富勒烯和碳纳米管)和金属有机骨架(MOF)的纳米尺度腔内氢分子的量子动力学、光谱和扩散的基本了解和全面的理论描述。这将提供一个广泛的理论框架以及定量预测，对于规划、分析和解释目前由世界各地的小组进行的这些系统的各种类型的光谱测量是必不可少的。一系列稳健的理论方法，从高维量子束缚态和散射方法，到扩散蒙特卡罗和路径积分模拟，都将应用于这些目标。这一建议的另一个目标是准确地确定纳米受限氢的多维、各向异性和非谐相互作用势，在某些情况下，还可以确定水与主体材料的相互作用势。要做到这一点，需要将复杂的量子动力学和从头算电子结构计算结合起来。本征态分辨计算将得到路径积分模拟的补充，旨在阐明分子氢的能级、自由能、空间分布和扩散的温度和浓度依赖关系，特别是在笼状水合物和MOF中。将氢作为一种清洁高效的能源载体大规模使用的一个主要障碍是开发安全和经济地储存它的方法。其中一种可能性目前正在全球范围内被纳米多孔材料吸收。定量地了解分子氢在这种条件下的性质，并表征氢与各种宿主环境的相互作用，对于旨在合理设计新的储氢介质的联合实验和理论工作是至关重要的。如果成功，开发高效储氢材料的挑战将对新兴能源技术产生巨大影响。这项研究将由纽约大学的研究生和本科生进行，包括那些来自传统上代表性不足的群体的学生。此外，我们的一位实验合作者Stephen Fitzgerald教授在一所本科院校(Oberlin)工作，他的学生将直接参与到这个项目中来。

Zlatko Bacic (PI) and Mark E. Tuckerman (co-PI) of New York University are supported by an award from the Chemical Structures, Dynamics and Mechanisms program of the Chemistry Division for a computational study aimed at achieving a fundamental understanding and a comprehensive theoretical description of the quantum dynamics, spectroscopy, and diffusion of hydrogen molecules inside the nanoscale cavities of diverse host materials, such as clathrate hydrates, fullerenes and carbon nanotubes, and metal-organic frameworks (MOFs). This will provide a broad theoretical framework, as well as quantitative predictions, indispensable for the planning, analysis, and interpretation of various types of spectroscopic measurements of these systems presently carried out by groups around the world. An array of robust theoretical approaches, ranging from high-dimensional quantum bound state and scattering methods to diffusion Monte Carlo and path integral simulations, will be brought to bear on these objectives. Another goal of this proposal is the accurate determination of multidimensional, anisotropic and anharmonic interaction potentials of the nanoconfined hydrogen, and in certain cases H2O, with the host materials. Accomplishing this will involve the combination of sophisticated quantum dynamics and ab initio electronic structure calculations. The eigenstate-resolved calculations will be complemented by path integral simulations directed at elucidating the temperature and concentration dependence of the energetics, free-energetics, spatial distributions, and diffusion of molecular hydrogen, especially in bulk clathrate hydrates and MOFs. A major hurdle for the large-scale use of hydrogen as a clean and efficient energy carrier is developing ways to store it safely and economically. One possibility currently under intense investigation worldwide absorption in nanoporous materials. Quantitative understanding of the properties of molecular hydrogen under such conditions, and characterization of the interactions of hydrogen with various host environments is essential in joint experimental and theoretical efforts aimed at rational design of new media for hydrogen storage. If met, the challenge of developing efficient hydrogen-storage materials will have an enormous impact on emerging energy technologies. This research will be carried out by graduate and undergraduate students at NYU, including those from traditionally underrepresented groups. In addition, one of our experimental collaborators, Prof. Stephen FitzGerald, is at an undergraduate institution (Oberlin), and his students will be directly involved in the project.