RUI: Double Photoionization to Probe Electron Correlation in Molecular Targets with more than Two Electrons

电子在原子和分子中的行为是我们理解物质系统的基础。从将分子结合在一起的基本化学键到宏观物质的整体特性，电子在很大程度上决定了液体和固体的化学组成和物理特性。量子力学告诉我们物质在原子这样小的尺度上的真实性质，但是准确地表示哪怕是最简单的分子也是具有挑战性的。尽管如此，从最基本的层面上研究物质还有很多东西要学，包括更好地理解电子相关的结果，电子相关在很大程度上决定了物质在所有长度尺度上的行为。电子相关性超越了电子相互排斥的事实；电子以基本的方式不断地相互注意，比如自旋相互作用，了解这些相互作用可以更好地告诉我们宇宙的基本结构。双光离研究，在一个足够能量的光子可以在一个事件中从材料中移除两个电子，直接探测电子的相关性。这项研究将推进精确的方法来描述像水（H2O）这样有许多电子的分子中的双光离。目的是更好地理解这些更复杂目标中的电子相关性，并进一步深入了解分子中电子的基本相互作用。这种理解一旦发展起来，就会为涉及化学和材料的多种技术应用提供信息，这些技术应用对高科技社会至关重要。该项目将研究具有两个以上电子的简单分子的单光子吸收（双光电离）去除的两个电子的电子相关性，以便更好地理解多电子目标受额外复杂性（超出H2）影响的方式。从第一原理描述这些事件的理论计算将应用于具有许多电子的目标，这些电子在光电离事件之前，期间和之后继续与完全相关的电子相互作用。需要理论支持，以帮助告知和理解最近的实验测量双光离的水。希望这个项目可以进一步阐明更广泛的后果，即所有与分子结合的电子如何影响那些将进入连续体的电子，以及分子对称性和电子结构的后果如何影响从分子环境中流出的电子。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

The behavior of electrons in atoms and molecules is fundamental to our understanding of material systems. From the basic chemical bonds that hold molecules together to the bulk properties of macroscopic matter, electrons are largely responsible for the chemical makeup and physical properties of liquids and solids. Quantum mechanics has informed us of the true nature of matter at the small scale of the atom, but accurately representing even the simplest molecule is challenging. Still, there is much to be learned from studying matter at the most fundamental level, including a better understanding of the consequences of electron correlation that govern so much of how matter behaves at all length scales. Electron correlation goes beyond the fact that electrons repel each other; electrons continually notice each other in fundamental ways, like spin interactions, and learning about those interactions better informs us of the fundamental construction of our universe. Double photoionization studies, where a photon of sufficient energy can remove two electrons from a material in a single event, directly probes electron correlation. This research will advance precise methods to describe double photoionization in molecules with many electrons, like water (H2O). The purpose is to better understand electron correlation in these more-complicated targets and gain further general insights into the fundamental interactions of electrons in molecules. This understanding, once developed, informs multiple technological applications involving chemistry and materials that are essential to a high-tech society.This project will investigate electronic correlation for two electrons removed by single-photon absorptions (double photoionization) for simple molecules with more than two electrons in order to better understand the ways that multi-electron targets are influenced by additional complexity (beyond H2). Theoretical calculations describing these events from first principles will be applied to targets with many electrons that continue to interact with the fully correlated electrons before, during and after the photoionization event. Theoretical support is needed to help inform and understand recent experimental measurements of double photoionization of water. It is hoped that this project can further elucidate the broader consequences of how all of the electrons bound to a molecule can affect those that will be moved into the continuum and how consequences of molecular symmetry and electronic structure impact the outgoing electrons from a molecular environment.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.