Theory of Negative Ion Formation by Adsorbed Molecules

吸附分子形成负离子的理论

• 批准号: 9319436
• 负责人: Philip Rous
• 金额: $ 14.1万
• 依托单位: University of Maryland Baltimore County
• 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: 1994-02-15 至 1998-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9319436&HistoricalAwards=false
• 关键词: Theory; Negative; Ion; Formation; Adsorbed

9319436 Rous A comprehensive theoretical description of resonance electron scattering by molecules adsorbed on solid surfaces will be developed and applied to understand the fundamental physics of negative ion formation at surfaces. The computational methodology will be based upon the layer-Kohn-Korringa-Rostoker theory which will fully incorporate the multiple scattering of the trapped electron by the substrate and surface barrier. Thus the influence of the unoccupied electronic structure of the substrate on the molecular resonance will be modelled. The dependence of resonance lifetime and energy upon the molecular adsorption height (above the surface), adsorption site and molecular orientation will be explored in order to elucidate the link between the adsorption geometry of a molecule and the behavior of the transient (resonance) state. %%% In a variety of electron and photon stimulated surface dynamical processes, short lived "resonance" electronic states localized mainly upon the adsorbed molecule are known to be important. The proposed work concerns itself with characterizing both the energy of these states and their lifetime via computationally intensive methodologies. The work will concentrate on how the presence of the nearby surface affects the resonance states of the free-space molecule and, further, how these states vary as a function of the location and orientation of the molecule relative to the surface. ***

9319436将开发并应用吸附在固体表面上的分子的共振电子散射的全面理论描述，以了解表面上负离子形成的基本物理。 计算方法将基于层 - 柯林加 - 康德加 - 促进者理论，该理论将完全融合了底物和表面屏障对捕获的电子的多重散射。 因此，将建模底物的空置电子结构对分子共振的影响。 将探索共振寿命和能量对分子吸附高度（表面上方），吸附位点和分子取向的依赖性，以阐明分子的吸附几何形状与瞬态（谐振）状态的行为之间的联系。 在各种电子和光子刺激的表面动力学过程中，众所周知，短暂的“共振”电子状态主要是在吸附分子上，已知很重要。 提出的工作涉及通过计算密集的方法来表征这些状态及其寿命的能量。 这项工作将集中于附近表面的存在如何影响自由空间分子的共振状态，此外，这些状态如何随着分子相对于表面的位置和方向而变化。 ***