Theoretical investigation of molecule-intense laser interactions using quantum chemical approaches

该奖项由2009年美国复苏和再投资法案（公法111 - 5）资助。超快强激光可以发展成为电子结构成像，探测超快动力学以及控制电子布居和分子碎片的强大工具。到目前为止，这些应用的原理验证实验只在少数分子上得到了证明。强激光分子相互作用的理论理解是至关重要的推广这些应用，它已被限制到过于简化的模型。这项工作探讨了量子化学（QC）方法的两个重要类型的这种相互作用：多光子电离和高次谐波产生。为了正确处理它们，必须解决高激发电子态和多电子效应的参与。这超出了仅处理基态或低激发态的QC方法的常规应用。将进行一系列基准计算，以验证这些方法，并确定主导这些过程的物理学。在理论水平上的方法的可能改进将与两个欧洲理论化学家合作。该项目将在强场分子物理学和理论化学方面产生影响。它将有助于开发新的工具来研究与最先进的激光器的化学反应。此外，它还将融入蒙大拿大学的本科物理化学教育。大三学生将有他们的第一次与计算化学的经验，以提高他们的电子结构和物质辐射场相互作用的理解。

AbstractThis award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5).Ultra-fast intense lasers can be developed into powerful tools for imaging electronic structures, probing ultra-fast dynamics, and controlling the electron population and molecular fragmentation. So far proof-of-principle experiments for these applications have been demonstrated for only a small number of molecules. Theoretical understanding of the intense laser-molecule interaction is crucial for the generalization of these applications and it has been limited to over-simplified models. This work explores quantum chemical (QC) methods for two important types of such interactions: multiphoton ionization and high harmonic generation. To properly treat them, the involvement of highly excited electronic states and many-electron effects have to be addressed. This is beyond conventional applications of the QC methods that treat only ground or low-lying excited states. A series of benchmark calculations will be performed to validate the methods and to identify the physics that dominates these processes. Possible improvement of the methods at theoretical level will be in collaboration with two European theoretical chemists. This project will have an impact in both strong field molecular physics and theoretical chemistry. It will help the development of new tools to study chemical reactions with state of the art lasers. In addition, it will also be integrated into the undergraduate physical chemistry education in the University of Montana. Junior year students will have their first experience with computational chemistry to enhance their understanding of electronic structure and matter-radiation field interactions.