RUI: Computational Methods for Molecular Resonances and Study of Electron-induced Reactions

RUI：分子共振的计算方法和电子诱导反应的研究

• 批准号: 1856775
• 负责人: Thomas Sommerfeld
• 金额: $ 12.51万
• 依托单位: Southeastern Louisiana University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-01-01 至 2023-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1856775&HistoricalAwards=false
• 关键词: RUI; Computational; Methods; Molecular; Resonances

Professor Thomas Sommerfeld of Southeastern Louisiana University is supported by an award from the Chemical Theory, Models and Computational Methods program in the Division of Chemistry. He develops computational methods to study the properties of negatively charged molecules called molecular anions. The presence of extra electrons (negative charges) can alter the strengths of the chemical bonds in a molecule. A chemical bond is formed when electrons are shared between nearby atoms. These shared electrons act like a "glue" that hold the atoms together to form a molecule. However, the presence of either too little or too much glue can weaken a chemical bond. If the bond is weakened enough, a molecular anion can become metastable and the bond can be easily broken. Alternatively, the metastable molecular anion can undergo a rearrangement and release an electron so that it can go back to having stronger, more stable bonds. Examples of areas in which these phenomena are applied are the etching of integrated circuits, studies involving chemical reactions in the upper atmosphere, radiation damage to living tissue, and some cancer therapies. Dr. Sommerfeld develops computer models of metastable anions. Making computer models of metastable anionic molecules is a challenge because one needs to simulate the quantum mechanical equations of motion describing all the electrons in the metastable anion, as well as all the electrons of all possible rearranged species that result from the released electron. Dr. Sommerfeld's goal is to identify a reliable, cost-efficient method to calculate the time it takes for electron release, a critical parameter for characterizing metastable anions. The project is being carried out at Southeastern Louisiana University, a predominantly undergraduate institution. Professor Sommerfeld engages lower income and underrepresented students in research projects involving high-level theory and sophisticated computational methods. In order to introduce undergraduates to this research, he also designs educational mini-projects using standard quantum chemistry methods,so that his students can be introduced to the research area step-by-step. In this project Dr. Sommerfeld studies electronically metastable states, so called resonance states, or resonances. He develops first-principles methods that characterize resonances and employs these methods to study electron-induced reactions. Computing both the energy and lifetime of a resonance is a challenging task for quantum chemistry because it combines an electron-scattering phenomenon with an electron-correlation problem. Dr. Sommerfeld pursues objectives that aim at improving the accuracy and reliability of one of the existing methods used to compute the energy of resonances and he pursues more specific projects aimed at implementing a set of reliable methods in systematic steps.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.

东南路易斯安那大学的 Thomas Sommerfeld 教授获得了化学系化学理论、模型和计算方法项目的奖项。 他开发了计算方法来研究带负电的分子（称为分子阴离子）的特性。额外电子（负电荷）的存在可以改变分子中化学键的强度。 当附近原子之间共享电子时，就会形成化学键。 这些共享的电子就像“胶水”一样，将原子粘合在一起形成分子。然而，胶水的存在太少或太多都会削弱化学键。 如果键足够弱，分子阴离子就会变得亚稳定，键很容易断裂。或者，亚稳态分子阴离子可以经历重排并释放电子，这样它就可以恢复到具有更强、更稳定的键。应用这些现象的领域的例子包括集成电路的蚀刻、涉及高层大气中的化学反应的研究、对活体组织的辐射损伤以及一些癌症治疗。 索末菲博士开发了亚稳态阴离子的计算机模型。制作亚稳态阴离子分子的计算机模型是一项挑战，因为需要模拟描述亚稳态阴离子中所有电子的量子力学运动方程，以及由释放的电子产生的所有可能重新排列物种的所有电子。 索末菲博士的目标是找到一种可靠、经济高效的方法来计算电子释放所需的时间，这是表征亚稳态阴离子的关键参数。该项目正在东南路易斯安那大学进行，该大学是一所以本科为主的机构。索末菲教授让收入较低且代表性不足的学生参与涉及高水平理论和复杂计算方法的研究项目。为了向本科生介绍这项研究，他还使用标准量子化学方法设计了教育迷你项目，以便让他的学生逐步了解该研究领域。在这个项目中，索末菲博士研究电子亚稳态，即所谓的共振态或共振。他开发了表征共振的第一原理方法，并利用这些方法来研究电子引发的反应。计算共振的能量和寿命对于量子化学来说是一项具有挑战性的任务，因为它结合了电子散射现象和电子相关问题。索末菲博士追求的目标是提高用于计算共振能量的现有方法之一的准确性和可靠性，并且他追求更具体的项目，旨在以系统的步骤实施一套可靠的方法。该奖项反映了 NSF 的法定使命通过使用基金会的智力价值和更广泛的影响审查标准进行评估，并被认为值得支持。

项目成果

Lifetimes of Be 3 2– and Mg 3 2– Cluster Dianions

Be 3 2– 和 Mg 3 2– 簇二阴离子的寿命

• DOI: 10.1021/acs.jpca.1c00770
• 发表时间: 2021
• 期刊: The Journal of Physical Chemistry A
• 作者: Davis, Jeremy U.;Phung, Quan Manh;Yanai, Takeshi;Ehara, Masahiro;Sommerfeld, Thomas
• 通讯作者: Sommerfeld, Thomas

Resonant states in cyanogen NCCN

氰的共振态 NCCN

• DOI: 10.1039/d0cp03333b
• 发表时间: 2020
• 期刊: Physical Chemistry Chemical Physics
• 影响因子: 3.3
• 作者: Nag, Pamir;Čurík, Roman;Tarana, Michal;Polášek, Miroslav;Ehara, Masahiro;Sommerfeld, Thomas;Fedor, Juraj
• 通讯作者: Fedor, Juraj

Computing resonance energies directly: method comparison for a model potential

直接计算共振能量：模型势的方法比较

• DOI: 10.1140/epjd/s10053-021-00332-z
• 发表时间: 2021
• 期刊: The European Physical Journal D
• 作者: Davis, Jeremy U.;Sommerfeld, Thomas
• 通讯作者: Sommerfeld, Thomas

Excluded-volume descriptors for dipole-bound anions: Amine N -oxides as a test case

偶极结合阴离子的排除体积描述符：胺氮氧化物作为测试用例

• DOI: 10.1063/1.5142624
• 发表时间: 2020
• 期刊: The Journal of Chemical Physics
• 作者: Sommerfeld, Thomas;Davis, Megan C.
• 通讯作者: Davis, Megan C.

Autodetachment over Broad Photon Energy Ranges in the Anion Photoelectron Spectra of [O 2 – M ] − ( M = Glyoxal, Methylglyoxal, or Biacetyl) Complex Anions

[O 2 → M ] →（M = 乙二醛、甲基乙二醛或联乙酰）复合阴离子的阴离子光电子谱中宽光子能量范围内的自分离

• DOI: 10.1021/acs.jpca.1c07163
• 发表时间: 2021
• 期刊: The Journal of Physical Chemistry A
• 作者: Dobulis, Marissa A.;McGee, Conor J.;Sommerfeld, Thomas;Jarrold, Caroline Chick
• 通讯作者: Jarrold, Caroline Chick