Fully Quantum Studies of Molecule-Surface Interactions at Finite Temperature

有限温度下分子-表面相互作用的全量子研究

• 批准号: 9318853
• 负责人: Bret Jackson
• 金额: $ 20.1万
• 依托单位: University of Massachusetts Amherst
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1994
• 资助国家: 美国
• 起止时间: 1994-04-01 至 1998-03-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9318853&HistoricalAwards=false
• 关键词: Fully; Quantum; Studies; Molecule; Surface

This study of molecules adsorbed on a solid surface is supported by the NSF Theoretical and Computational Chemistry program. The molecule-phonon interaction is treated quantum mechanically using a Hamiltonian operator that can include multiple phonons, as well as the hindered translational, rotational, and vibrational modes of the molecule, and all possible interactions of these degrees of freedom. Both weak (one phonon) and strong (multi-phonon) interactions can be described. The nature of the trapped state with regard to desorption, relaxation, and hot atom chemistry is treated. The effect of varying the component of beam energy parallel to the surface is also studied. Computer models are used in this research to study the motion of molecules adsorbed on solid surfaces. The goal is to gain fundamental knowledge of the principles of surface chemistry, which in turn relates to chemical processes of great practical importance such as heterogeneous catalysis. Computer modeling is a widely used theoretical tool for the study of such processes. The special role of this research project is to test the validity of various mathematical and physical approximations commonly employed in these computations. In particular, the laws of quantum mechanics, rather than classical mechanics, are applied, and the interaction of the molecule with one or more phonons (quantized lattice vibrations) are treated.

这项关于固体表面吸附分子的研究得到了美国国家科学基金会理论和计算化学项目的支持。分子-声子相互作用用量子力学处理，使用哈密顿算符，该算符可以包括多个声子，以及分子的受阻平移、旋转和振动模式，以及这些自由度的所有可能的相互作用。弱相互作用(单声子)和强相互作用(多声子)都可以描述。讨论了与脱附、弛豫和热原子化学有关的俘获态的性质。文中还研究了改变平行于表面的束流能量分量的影响。在这项研究中，使用计算机模型来研究吸附在固体表面的分子的运动。目标是获得表面化学原理的基本知识，而表面化学原理反过来又与具有重要实际意义的化学过程有关，如多相催化。计算机模拟是研究这类过程的广泛使用的理论工具。这项研究项目的特殊作用是测试这些计算中常用的各种数学和物理近似的有效性。特别是，应用了量子力学的定律，而不是经典的力学，并处理了分子与一个或多个声子的相互作用(量子化的晶格振动)。