Chemical Dynamics at Solid Surfaces

耶鲁大学的约翰·塔利（John Tully）得到了理论与计算化学计划的支持，他的研究重点是对固体表面动力学过程的原子水平理解。新的理论和计算工具将被创建并用于研究三个领域的特定化学问题。首先，将探索金属表面的动力学，以预测电子-空穴对跃迁对吸附能转移的贡献。研究了扫描隧道显微镜（STM）中振动模态相对强度和近似倾向规则的计算方法。第二，将发展混合量子-经典动力学，其目标是将传统的分子动力学模拟扩展到涉及电子跃迁和/或量子核运动的实际应用。最后，将开发和测试用于计算半导体和金属表面吸附态激发态能量和寿命的从头算方法，然后扩展到计算吸附离子共振态和激发态的能量和宽度。了解固体表面上的分子和电子行为对于获得驱动半导体加工等技术重要领域创新所需的见解非常重要。这项研究的结果预计将影响各种重要的化学应用，包括从STM中观察到的地形特征确定分子身份，以及对涉及电化学、凝聚相动力学和酶反应的多维过程的理解。

John Tully of Yale University is supported by the Theoretical and Computational Chemistry Program for research that focuses on the atomic-level understanding of dynamical processes at solid surfaces. New theoretical and computational tools will be created and used to study specific chemical problems in three areas. First, dynamics at metal surfaces will be explored to enable prediction of the contribution of electron-hole pair transitions to adsorbate energy transfer. Methods for computing the relative intensities of vibrational modes and approximate propensity rules in scanning tunneling microscopy (STM) will be developed. Second, mixed quantum-classical dynamics will be developed with the goal of extending conventional molecular dynamics simulations to practical applications involving electronic transitions and/or quantum nuclear motion. Finally, ab initio methods for computing energies and lifetimes of adsorbate excited states at semiconductor and metal surfaces will be developed and tested, then extended to calculating energies and widths of adsorbate-ion resonance states and excited states. Understanding molecule and electron behavior on solid surfaces is important for gaining insights needed to drive innovations in technologically important areas such as semiconductor processing. Outcomes from this research are expected to impact a variety of important chemical applications, including the determination of molecular identity from observed topographical features in STM, and the understanding of multi-dimensional processes such as those involved in electrochemistry, condensed phase dynamics, and enzyme reactions.